U.S. patent application number 09/795397 was filed with the patent office on 2002-11-28 for optical apparatus.
Invention is credited to Kawanami, Eriko, Noto, Goro, Onuki, Ichiro.
Application Number | 20020176148 09/795397 |
Document ID | / |
Family ID | 27481093 |
Filed Date | 2002-11-28 |
United States Patent
Application |
20020176148 |
Kind Code |
A1 |
Onuki, Ichiro ; et
al. |
November 28, 2002 |
Optical apparatus
Abstract
To provide an optical apparatus which controls an interface
state to change a focal length by using an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes, and in particular an optical apparatus that controls a
duty ratio of alternating current voltage applied to said
electrodes for changing said interface form.
Inventors: |
Onuki, Ichiro;
(Kawasaki-shi, JP) ; Noto, Goro; (Tokyo, JP)
; Kawanami, Eriko; (Kawasaki-shi, JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Family ID: |
27481093 |
Appl. No.: |
09/795397 |
Filed: |
March 1, 2001 |
Current U.S.
Class: |
359/253 ;
359/254 |
Current CPC
Class: |
H04N 5/23241 20130101;
G02B 3/14 20130101; G03B 13/32 20130101; H04N 5/23296 20130101;
H04N 5/369 20130101; G02B 26/005 20130101 |
Class at
Publication: |
359/253 ;
359/254 |
International
Class: |
G02F 001/03; G02F
001/07 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 3, 2000 |
JP |
2000-058295 |
Mar 3, 2000 |
JP |
2000-058312 |
Mar 3, 2000 |
JP |
2000-058377 |
Jun 22, 2000 |
JP |
2000-187227 |
Claims
What is claimed is:
1. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes; a power supply circuit which applies predetermined
alternating current voltage to said electrodes in order to change
said interface form; and an applied voltage controlling circuit
which controls said alternating current voltage to be applied, the
applied voltage controlling circuit having configuration for
controlling a duty ratio of said alternating current voltage and
changing said interface form by controlling the duty ratio.
2. The optical apparatus according to claim 1, wherein said power
supply circuit has configuration for applying alternating current
voltage having rectangular wave of which peak voltage and frequency
are substantially an invariant.
3. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes; a power supply circuit which applies predetermined
alternating current voltage to said electrodes in order to change
said interface form; and an applied voltage controlling circuit
which controls said alternating current voltage to be applied, the
applied voltage controlling circuit having configuration for
controlling a frequency of said alternating current voltage and
changing said interface form by controlling the frequency.
4. The optical apparatus according to claim 3, wherein said power
supply circuit has configuration for applying alternating current
voltage having rectangular wave of which peak voltage and duty
ratio are substantially an invariant.
5. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes; a power supply circuit which applies predetermined
alternating current signal to said electrodes in order to change
said interface form; a power supply controlling circuit which
controls said alternating current signal to be applied; and a
switch circuit which switches a frequency of said alternating
current signal by said power supply controlling circuit according
to an operational control state of the optical apparatus.
6. The optical apparatus according to claim 5, wherein said switch
circuit renders said alternating current voltage as a first
frequency when starting to apply voltage to said optical element,
and switches said alternating current voltage to a second frequency
when having completed deformation of said optical element.
7. The optical apparatus according to claim 5, wherein said optical
apparatus has means for photography, and said switch circuit
renders said alternating current voltage as a first frequency when
preparing for recording an image by the means for photography, and
switches said alternating current voltage to a second frequency
when photography for recording an image by said means for
photography.
8. The optical apparatus according to claim 1, wherein said first
liquid and said second liquid have substantially different in
refractive indexes, and their interface is sealed in said container
in a state of forming a large radius when said voltage is not
applied.
9. The optical apparatus according to claim 1, wherein said first
liquid and said second liquid have substantially equal in
refractive indexes, and their interface is sealed in said container
in a state of forming an abbreviated flat when said voltage is not
applied.
10. The optical apparatus according to claim 1, wherein said
electrodes comprises a first electrode and a second electrode
insulated from said first liquid, the first electrode provided so
as to conduct to said first liquid.
11. The optical apparatus according to claim 1, wherein said first
electrode is provided so as to conduct to said first liquid from a
side of said container.
12. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes; a power supply circuit which applies alternating
current voltage of first applied voltage to said electrodes in
order to change said interface form to predetermined form; and an
applied voltage controlling circuit which controls said alternating
current voltage, said applied voltage controlling circuit applying
second applied voltage that is transitional before applying said
first applied voltage.
13. The optical apparatus according to claim 12, wherein said
second applied voltage is voltage of a value corresponding to
ambient temperature.
14. The optical apparatus according to claim 12, wherein an applied
voltage controlling circuit is configured to set an applied
waveform of said second voltage based on detection results of
ambient temperature of said optical element.
15. The optical apparatus according to claim 12, wherein a voltage
value of said first applied voltage is set based on detection
results of ambient temperature of said optical element.
16. The optical apparatus according to claim 12, wherein
application time of said second applied voltage is set based on
detection results of ambient temperature of said optical
element.
17. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes; image recording means which records an optical image of
light flux passing through the optical element; a power supply
circuit which applies predetermined voltage to said electrodes in
order to change said interface form; and an inhibiting circuit
which inhibits image recording operation by said recording means
from being performed at least before certain time passes from a
start of power supply by the power supply means.
18. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes; a power supply circuit which applies first voltage to
said electrodes in order to change said interface form; and an
applied voltage controlling circuit which, before applying a first
voltage value, applies a second voltage value that is
transitionally set lower or higher than the first voltage value,
irrespective of direction of change of said applied voltage to the
first voltage.
19. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes; and a determining circuit which determines a voltage
value to be applied to said electrodes according to a direction of
changing said interface form.
20. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes; a power supply circuit which applies predetermined
voltage to said electrodes in order to change said interface form;
and a controlling circuit which, after applying voltage to said
optical element by said power supply circuit, disables application
of voltage to said optical element by said power supply circuit by
terminating a series of operation in the optical apparatus.
21. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes; a power supply circuit which applies predetermined
voltage to said electrodes in order to change said interface form;
an operating member which renderes a state of voltage to said
optical element by said power supply means variable in order to
change optical characteristics of said optical element to a desired
state; and an inhibiting circuit which inhibits application of
voltage to said optical element when operations of said operating
member are not performed for predetermined time.
22. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and electrodes provided in
the container and of which optical characteristics change according
to change of interface form due to application of voltage to the
electrodes; a power supply circuit which applies predetermined
voltage to said electrodes in order to change said interface form;
storing means which stores applied voltage in the last operation of
said optical element; and a setting circuit which, in applying said
voltage to said optical element, sets applied voltage to said
optical element based on a stored value of said storing means.
23. The optical apparatus according to claim 22, wherein said
optical element is a variable focal lens.
24. The optical apparatus according to claim 22, wherein said
optical element is an eyesight adjustment lens built into an
observation optical system.
25. An optical apparatus comprising: an optical element having
configuration wherein first liquid and second liquid that does not
mutually mix with the first liquid are sealed in a container with
their interface in a predetermined form and application of voltage
to said first liquid changes a radius of curvature and height of a
spherical surface formed by said interface to be in a state
corresponding to said voltage value so as to change a focal length;
a changing circuit which changes said voltage value according to
operation of a zoom operating member; and a power supply circuit
which starts application of voltage to said first liquid by
operating said zoom operating member and stopping application of
the voltage to said first liquid when a series of photography
operations are completed.
26. An optical apparatus comprising: an optical element having
configuration wherein first liquid and second liquid that does not
mutually mix with the first liquid are sealed in a container with
their interface in a predetermined form and application of voltage
to said first liquid changes the form of said interface to be in a
state corresponding to said voltage value so as to change optical
characteristics; a changing circuit which changes said voltage
value according to operation of an operating member; and a power
supply circuit which stops application of said voltage when
operation of a photography starting operation section is not
performed within predetermined time from termination of operation
of said operating member, and stops application of said voltage
after operation of the photography starting operation section is
completed when operation of said photography starting operation
section is performed within said predetermined time.
27. The optical apparatus according to claim 26, wherein said power
supply circuit stops application of said voltage at the time when a
series of photography operations are completed after said
predetermined time passed.
28. The optical apparatus according to claim 26, wherein when
photography operations are completed within said predetermined
time, said power supply circuit stops application of said voltage
after waiting until a predetermined time has elapsed from the
completion.
29. An optical apparatus comprising: an optical element having
configuration wherein first liquid and second liquid that does not
mutually mix with the first liquid are sealed in a container with
their interface in a predetermined form and application of voltage
to said first liquid changes the form formed on said interface to
be in a state corresponding to said voltage value so as to change
optical characteristics; an operating member which changes said
voltage value; a power supply circuit which starts application of
voltage to said first liquid in a state of preparation for starting
photography; a storing circuit which, before the power is turned
off, stores data corresponding to a voltage value finally changed
by said operating member; and a controlling circuit which, when the
power is turned off and then turned on and said voltage is applied
in a state of preparation for starting next photography, applies a
voltage value corresponding to data stored on said storing
circuit.
30. An optical apparatus comprising: an optical element having
configuration wherein first liquid and second liquid that does not
mutually mix with the first liquid are sealed in a container with
their interface in a predetermined form and application of voltage
to said first liquid changes a radius of curvature and height of a
spherical surface formed by said interface to be in a state
corresponding to said voltage value so as to change transmittance;
and a controlling circuit which controles said voltage value
according to a luminance value, said optical element placed in a
photography optical path and adopted as a light quantity
controlling element.
31. The optical apparatus according to claim 30, wherein said
optical element is an element having configuration wherein said
first liquid has a predetermined light absorption characteristic
and thickness to a surface of a container of said first liquid is
changed according to a radius of curvature and height of a
spherical surface formed by said interface so as to change
transmittance.
32. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and of which optical
characteristics change according to change of interface form due to
application of voltage between first and second electrodes provided
in the container; a power supply circuit which applies
predetermined voltage to said electrodes in order to change said
interface form; controlling means which controls said applied
voltage; and an electrostatic capacity detecting circuit which
detects electrostatic capacity between said first and second
electrodes.
33. The optical apparatus according to claim 32, wherein a
controlling circuit for controlling interface form to be
predetermined one based on electrostatic capacity detected on said
electrostatic capacity detecting circuit is provided.
34. The optical apparatus according to claim 33, wherein it is
determined whether or not a detected value of the electrostatic
capacity is in a allowable range based on the electrostatic
capacity detected on said electrostatic capacity detecting circuit
to control voltage applied to said optical element.
35. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and of which optical
characteristics change according to change of interface form due to
application of voltage between a first and second electrodes
provided in the container; a power supply circuit which applies
predetermined voltage to said electrodes in order to change said
interface form; a detecting circuit which detects change of said
interface form; and a controlling circuit which controls said
applied voltage signal based on information detected on the
detecting circuit.
36. An optical apparatus comprising: an optical element having a
container sealing first liquid that is conductive or polarized and
second liquid that does not mutually mix with the first liquid with
their interface in a predetermined form and of which optical
characteristics change according to change of interface form due to
application of voltage between a first and second electrodes
provided in the container; a power supply circuit which applies
predetermined voltage to said electrodes in order to change said
interface form; controlling means which controls said applied
voltage; an electrostatic capacity detecting circuit which detects
electrostatic capacity between said first and second electrodes; a
state determining circuit which determines a state of the optical
apparatus according to a capacity value detected on the detecting
circuit.
37. The optical apparatus according to claim 36, wherein said
determining circuit determines it to be a failure when a detected
capacity value is a predetermined value.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an optical apparatus
including an optical element utilizing electro-wetting
(electro-capillarity), and in particular to power supply means for
driving the element.
[0003] 2. Related Background Art
[0004] Of optical systems built into optical apparatuses such as a
still camera and a video camera, those capable of changing a focal
length mostly change a focal length of the entire optical system by
mechanically moving part of lenses (or a lens group) comprising the
optical system in a direction of an optical axis.
[0005] For instance, Japanese Patent No. 2633079 shows
configuration wherein, of a zoom lens-barrel comprising a first
group of lenses moving in a direction of an optical axis by
zooming, a first group of lens-barrels moving in the optical axis
direction on movement of the first group of lenses and a cam barrel
moving in the optical axis direction due to movement of the first
group of lens-barrels, the first group of lens-barrels fit an outer
diameter side of a fixed barrel, the cam barrel fits an inner
diameter side of the fixed barrel, and a front part of the cam
barrel fits an inner diameter side of the first group of
lens-barrels, and the cam barrel is moved in the optical axis
direction so as to move the first group of lenses and perform
zooming.
[0006] Thus, in the case of changing a focal length by mechanically
moving lenses (or a lens group) in a direction of an optical axis,
there is a deficiency, that is, complicated mechanical structure of
the optical apparatus.
[0007] To solve this deficiency, there is a case of rendering a
focal length variable by changing optical characteristics of a lens
itself.
[0008] For instance, Japanese Patent Application Laid-Open No.
8-114703 provides a varifocal lens wherein, in the case where
hydraulic fluid is filled in a pressure chamber at least one side
of which is comprised of a transparent elastic diaphragm, and the
transparent elastic diaphragm is deformed by hydraulic fluid
pressure exerted on the diaphragm to render a focal length under
variable control, the deformed form of the transparent elastic
diaphragm is optimized so as to make lens aberration less likely to
occur, and also hydraulic fluid pressure in the pressure chamber is
measured with a pressure sensor formed on the transparent elastic
diaphragm so that, by adjusting hydraulic fluid pressure based on
that value, change of a focal length due to thermal expansion and
contraction of hydraulic fluid and so on can also be
controlled.
[0009] In addition, in Japanese Patent Application Laid-Open No.
11-133210, an electric potential difference is given between a
first electrode and a conductive elastic plate to lessen the space
between them by generating attraction by Coulomb's force, and it
consequently becomes possible, by using volume of transparent
liquid excluded from the space between them, to convex and deform a
central portion of the transparent elastic plate with respect to
its back facing the transparent liquid. Then, a convex lens is
formed by the convex-deformed transparent elastic plate,
transparent plate and the transparent liquid filled between them,
so that power of this convex lens is adjusted by the above electric
potential difference to constitute a varifocal lens.
[0010] On the other hand, a varifocal lens using
electro-capillarity is disclosed by WO99/18456. If this technique
is used, electrical energy can be used directly to change form of a
lens formed by an interface between the first and second liquid, so
that it becomes possible to make the lens varifocal without
mechanically moving it.
[0011] However, the above-mentioned related arts have the following
problems. For instance, the above Japanese Patent Application
Laid-Open No. 8-114703 describes an actuator controlling apparatus
for driving an actuator wherein, as the actuator, a unimorph
mechanism by a piezoelectric element formed on a transparent
elastic diaphragm is utilized. However, this known technique
requires high rigidity of the elastic deformed portion, and
consequently has a fault of requiring large amounts of electric
power.
[0012] Moreover, the above Japanese Patent Application Laid-Open
No. 11-133210 also requires high rigidity of the elastic deformed
portion, and consequently has a fault of requiring large amounts of
electric power likewise.
[0013] Furthermore, the above WO99/18456 can change optical power
with small amounts of electric power since there is no mechanical
movable part, but there is no detailed description of power means,
and a technique for controlling optical power with precision and
small amounts of electric power is not disclosed.
SUMMARY OF THE INVENTION
[0014] One aspect of the invention is to provide an optical
apparatus which controls, in a short time and properly or in a
state of reduced power consumption or in a state suited to a
photography sequence, an optical element comprising a container
sealing first liquid that is conductive or polarized and second
liquid that does not mutually mix with the first liquid with their
interface in a predetermined form and electrodes provided in the
container and of which optical characteristics change according to
change of interface form due to application of voltage to the
electrodes.
[0015] One aspect of the invention is to duty-drive the element for
the above object.
[0016] One aspect of the invention is to drive the element by
controlling a frequency for the above object.
[0017] One aspect of the invention is to provide an apparatus for,
on driving the element, transitionally applying first voltage and
switching to second voltage from that state for the above
object.
[0018] One aspect of the invention is to provide an apparatus for,
on using the element as an optical system of a camera, inhibiting
photography from being performed before predetermined time passes
from application of voltage to the element for the above
object.
[0019] One aspect of the invention is to provide an apparatus for
stopping application of voltage when operation of an operating
member for changing a voltage signal to be applied to the element
is not performed for predetermined time for the above object.
[0020] One aspect of the invention is to provide an apparatus for
storing a voltage signal applied to the element at last photography
time and applying a voltage signal corresponding to this stored
value at next photography time for the above object.
[0021] One aspect of the invention is to provide an apparatus for
detecting electrostatic capacity of an optical element to determine
and control a state of interface form of an optical apparatus for
the above object.
[0022] Other objects of the present invention will become clearer
from the embodiments described hereunder by using the drawings.
BRIEF DECSRIPTION OF THE DRAWINGS
[0023] FIGS. 1A, 1B and 1C are diagrams describing power supply
controlling methods of an optical element in the first embodiment
of the present invention respectively;
[0024] FIG. 2 is a sectional view of an optical element in the
first embodiment of the present invention;
[0025] FIG. 3 is a diagram describing operation on applying voltage
to an optical element in the first embodiment of the present
invention;
[0026] FIGS. 4A and 4B are diagrams describing operation on
applying DC voltage to an optical element of the present invention
respectively;
[0027] FIGS. 5A and 5B are diagrams describing operation on
applying AC voltage to an optical element of the present invention
respectively;
[0028] FIG. 6 is a conceptual rendering of a driving frequency and
a response in an optical element of the present invention;
[0029] FIG. 7 is a diagram describing an optical element and power
supply means in the first embodiment of the present invention;
[0030] FIGS. 8A, 8B, 8C, 8D and 8E are diagrams describing
operation of power supply means in the first embodiment of the
present invention;
[0031] FIG. 9 is a block diagram of an optical apparatus in the
first embodiment of the present invention;
[0032] FIG. 10 is a control flow diagram of an optical apparatus in
the first embodiment of the present invention;
[0033] FIGS. 11A, 11B and 11C are diagrams describing a power
supply controlling method in the first embodiment of the present
invention;
[0034] FIG. 12 is a block diagram of an optical apparatus in the
second embodiment of the present invention;
[0035] FIG. 13 is a control flow diagram of an optical apparatus in
the second embodiment of the present invention;
[0036] FIGS. 14A, 14B and 14C are diagrams describing power supply
controlling methods in the second embodiment of the present
invention respectively;
[0037] FIGS. 15A, 15B and 15C are diagrams describing power supply
controlling methods in the second embodiment of the present
invention respectively;
[0038] FIG. 16 is a sectional view of an optical element in the
third embodiment of the present invention;
[0039] FIGS. 17A and 17B are diagrams describing operation on
applying voltage to an optical element in the third embodiment of
the present invention respectively;
[0040] FIG. 18 is a block diagram of an optical apparatus in the
third embodiment of the present invention;
[0041] FIG. 19 is a control flow diagram of an optical apparatus in
the third embodiment of the present invention;
[0042] FIGS. 20A, 20B, 20C and 20D are diagrams describing power
supply controlling methods in the third embodiment of the present
invention respectively;
[0043] FIGS. 21A, 21B, 21C and 21D are diagrams describing power
supply controlling methods in the third embodiment of the present
invention respectively;
[0044] FIG. 22 is a block diagram of an optical apparatus in the
fourth embodiment of the present invention;
[0045] FIG. 23 is a main control flow diagram of an optical
apparatus in the fourth embodiment of the present invention;
[0046] FIG. 24 is a sub-control flow diagram of an optical
apparatus in the fourth embodiment of the present invention;
[0047] FIGS. 25A, 25B, 25C and 25D are diagrams describing
relationship between applied voltage and change of interface form
of an optical element in the fourth embodiment of the present
invention respectively;
[0048] FIG. 26 is an example of temperature correction table in the
fourth embodiment of the present invention;
[0049] FIG. 27 is a block diagram of an optical apparatus in the
fifth embodiment of the present invention;
[0050] FIG. 28 is a main control flow diagram of an optical
apparatus in the fifth embodiment of the present invention;
[0051] FIG. 29 is a sub-control flow diagram of an optical
apparatus in the fifth embodiment of the present invention;
[0052] FIGS. 30A, 30B, 30C and 30D are diagrams describing
relationship between applied voltage and change of interface form
of an optical element in the fifth embodiment of the present
invention respectively;
[0053] FIG. 31 is a main control flow diagram of an optical
apparatus in the sixth embodiment of the present invention;
[0054] FIG. 32 is a sub-control flow diagram of an optical
apparatus in the sixth embodiment of the present invention;
[0055] FIGS. 33A and 33B are diagrams describing applied voltage
control in the sixth embodiment of the present invention
respectively;
[0056] FIG. 34 is a block diagram of an optical apparatus in the
seventh embodiment of the present invention;
[0057] FIG. 35 is a main control flow diagram of an optical
apparatus in the seventh embodiment of the present invention;
[0058] FIG. 36 is a sub-control flow diagram of an optical
apparatus in the seventh embodiment of the present invention;
[0059] FIG. 37 is a block diagram of an optical element in the
eighth embodiment of the present invention;
[0060] FIGS. 38A and 38B are diagrams describing operation on
applying voltage to an optical element in the eighth embodiment of
the present invention respectively;
[0061] FIG. 39 is a diagram describing optical action of an optical
element in the eighth embodiment of the present invention;
[0062] FIG. 40 is a block diagram of an optical apparatus in the
eighth embodiment of the present invention;
[0063] FIG. 41 is a control flow diagram of an optical apparatus in
the ninth embodiment of the present invention;
[0064] FIG. 42 is a block diagram of an optical apparatus in the
tenth embodiment of the present invention;
[0065] FIG. 43 is a flowchart showing main control of an optical
apparatus in the tenth embodiment of the present invention;
[0066] FIG. 44 is a flowchart showing a subroutine of an optical
apparatus in the tenth embodiment of the present invention;
[0067] FIGS. 45A, 45B and 45C are detail drawings describing
operation of an optical element in the eleventh embodiment of the
present invention respectively;
[0068] FIG. 46 is a diagram describing transmittance distribution
of an optical element in the eleventh embodiment of the present
invention;
[0069] FIG. 47 is a block diagram of an optical apparatus in the
eleventh embodiment of the present invention;
[0070] FIG. 48 is a flowchart showing control of an optical
apparatus in the eleventh embodiment of the present invention;
[0071] FIG. 49 is a block diagram of electrostatic capacity
detecting means and power supply means and a sectional view of an
optical element in the twelfth embodiment of the present
invention;
[0072] FIG. 50 is a diagram of relationship between driving voltage
and detecting voltage in the twelfth embodiment of the present
invention;
[0073] FIGS. 51A, 51B, 51C, 51D and 51E are diagrams describing
voltage waveform outputted from an amplifier of a power supply
means related to the twelfth embodiment of the present invention
respectively;
[0074] FIG. 52 is a block diagram of an optical apparatus
incorporating an optical element related to the twelfth embodiment
of the present invention;
[0075] FIG. 53 is a control flow diagram of an optical apparatus
related to the twelfth embodiment of the present invention;
[0076] FIG. 54 is a control flow diagram of an optical apparatus
related to the twelfth embodiment of the present invention;
[0077] FIG. 55 is a block diagram of an optical apparatus
incorporating electrostatic capacity detecting means and power
supply means and an optical element related to the thirteenth
embodiment of the present invention;
[0078] FIG. 56 is a control flow diagram of an optical apparatus
related to the thirteenth embodiment of the present invention;
and
[0079] FIG. 57 is a control flow diagram of an optical apparatus
related to the thirteenth embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0080] [First Embodiment]
[0081] FIGS. 1A to 1C through FIGS. 11A to 11C are explanatory
views for describing a configuration of a first embodiment of the
present invention, and FIG. 2 is a sectional view showing a
configuration of an optical element of this embodiment. With
reference to FIG. 2, at first, the configuration and a producing
method of this embodiment will be described.
[0082] In FIG. 2, reference numeral 101 denotes the optical element
of the present invention in its entirety while reference numeral
102 denotes a transparent substrate made of transparent acryl in
which a concave portion is provided in the center thereof. On the
upper face of the transparent substrate 102, a transparent
electrode (ITO) 103 made of indium tin oxide is formed by
sputtering, and in tight contact with the upper face thereof, an
insulating layer 104 made of transparent acryl is provided. The
insulating layer 104 is formed by dripping replica resin onto the
center of the above described transparent electrode 103, and
pushing it with a glass plate for flattening and smoothing its
surface, and thereafter radiation by UV is implemented for
hardening and forming. Onto the upper surface of the insulating
layer 104, a shading cylindrical container 105 is fixed by gluing,
and onto it a cover plate 106 made of transparent acryl is fixed by
gluing, and moreover onto it a diaphragm plate 107 having opening
of diameter D3 in the center is disposed. In the above described
configuration, a sealed space of a predetermined volume enclosed by
the insulating layer 104, the container 105 and the upper cover
106, that is, a box having a liquid chamber is formed. In addition,
surface treatment described below is implemented on the wall of the
liquid chamber.
[0083] At first, a water-repelling treatment agent is applied to
the central upper surface of the insulating layer 104 within the
range of the diameter Dl to form a water-repelling film 111. For
the water-repelling agent, fluoride compounds, etc. are suitable.
In addition, in the outskirt range beyond the diameter D1 on the
upper surface of the insulating layer 104, hydrophilic treatment
agent is applied so that a hydrophilic film 112 is formed. As
hydrophilic agent, surface-active agent and hydrophilic polymer,
etc. are suitable. On the other hand, on the bottom surface of the
cover plate 106, hydrophilic treatment is implemented within a
range of the diameter D2 so that a hydrophilic film 113 having
properties as the above described hydrophilic film 112 is formed.
In addition, all the configuring members having been described so
far are shaped rotary symmetrical around an optical axis 123.
Moreover, a hole is formed in a portion of the container 105, and
thereto a stick-like electrode 125 is inserted and sealed by
adhesive agent to maintain sealing state of the above described
liquid chamber. In addition, power supply means 126 are brought
into connection with the transparent electrode 103 and the
stick-like electrode 125 and with operation on a switch 127 a
predetermined voltage is arranged to be applicable between the both
electrodes.
[0084] The liquid chamber configured as described so far will be
filled with two kinds of liquid as described below. At first, onto
the water-repelling film 111 on the insulating layer 104 a
predetermined quantity of a second liquid 122 is dripped. The
second liquid 122 is colorless and transparent, and silicone oil
which has specific gravity of 1.06 and a refractive index of 1.49
in a room temperature will be used. On the other hand, the
remaining space inside the liquid chamber is filled with conductive
or polarized first liquid 121. The first liquid 121 is electrolytic
solution, which is a mixture of water and ethyl-alcohol at a
predetermined ratio and moreover to which a predetermined quantity
of salt (sodium chloride) is added, with specific gravity 1.06 and
with refractive index 1.38 under a room temperature. That is, for
the first and the second liquid, liquids which have the same
specific gravity and are insoluble each other are selected. There,
the both liquids form an interface 124 and each of them exists
independently without being mixed together.
[0085] Next, the shape of the above described interface will be
described. At first, in the case where no voltage is applied to the
first liquid, the shape of the interface 124 is determined by
interfacial tension between the both liquids, interfacial tension
between the first liquid and the water-repelling film 111 or the
hydrophilic film 112 on the insulating layer 104, interfacial
tension between the second liquid and the water-repelling film 111
or the hydrophilic film 112 on the insulating layer 104, and volume
of the second liquid. In this embodiment selection of materials is
implemented so that interfacial tension between silicone oil being
material for the second liquid 122 and the water-repelling film 111
becomes relatively small. That is, wet-aptness is high between the
both materials and therefore the outer periphery of lens-shaped
drops which the second liquid 122 form tends to expand and is
stabilized where the outer periphery corresponds with the
application region of the water-repelling film 111. That is, the
diameter A1 of the bottom surface of the lens which the second
liquid forms is equal to the diameter D1 of the water-repelling
film 111. On the other hand, since the specific gravity of the both
liquids is the same as described above, gravity are not
influential. Then the interface 124 becomes spherical, and the
radius of curvature as well the height hi thereof are determined by
the volume of the second liquid 122. In addition, thickness of the
first liquid on the optical axis will be t1.
[0086] On the other hand, when the switch 127 is operated to close
so that a voltage is applied to the first liquid 121, electric
capillary phenomenon causes the interfacial tension between the
first liquid 121 and the hydrophilic film 112 to decrease and the
first liquid trespass the interface between the hydrophilic film
112 and the water-repelling film 111 to penetrate into region on
the water-repelling film 111. Consequently, as in FIG. 3, the
diameter of the bottom surface of the lens which the second liquid
forms decreases from A1 to A2 while its height increases from h1 to
h2. In addition, thickness of the first liquid on the optical axis
will be t2. Thus, application of voltage to the first liquid 121
changes balance in the interfacial tensions of the two kinds of
liquid so that the interface between the two liquids is deformed.
Accordingly, such an optical element that can freely deform the
interface 124 with voltage control on the power supply means 126
can be realized. In addition, the first as well as the second
liquid have different refractive indexes to provide with a power as
an optical lens and therefore the optical element 101 will be a
variable focusing lens with deformation of the interface 124.
[0087] Moreover, since compared with FIG. 2 the interface 124 in
FIG. 3 is shorter in the radius of curvature, the optical element
101 in the state shown in FIG. 3 has a focal length shorter than
that in the state a shown in FIG. 2.
[0088] FIGS. 4A and 4B are explanatory views conceptually showing
deformation process of the interface 124 of the optical element 101
when the power supply means 126 are caused to give rise to a direct
voltage.
[0089] In FIG. 4A, a step-like direct current voltage of voltage
V.sub.0 is applied to the optical element 101 at time t.sub.0. At
this time, the interface which both liquids form in the optical
element 101 responds as a curve shown in FIG. 4B. That is, the
deformed amount starts with a predetermined time constant to reach
a value of 95% of the final deformed amount .delta.o at time
t.sub.12, and gets further closer toward .delta.o, but regardless
of the voltage being applied, the subsequent deformed amount
decreases. This is originated in that in FIG. 3 charges are
gradually implanted into the insulating layer 104 and electric
capillary phenomenon is caused to decrease. In order to avoid this
phenomena, it is described in page 158 of Comptes Rendus des
Seances dei'Academie des Science 317 (1993) that an alternate
current electric power supply of around 50 to 3 kHz can be
successfully used as the power supply means 126.
[0090] Incidentally, the reference character .delta. conceptually
denotes interface deformed amount, and does not mean a numerical
value directly describing height or contact angle of an interface
but intensity of electric capillary phenomenon.
[0091] FIGS. 5A and 5B are explanatory views conceptually showing
deformation process of the interface 124 of the optical element 101
when the power supply means 126 are caused to give rise to an
alternate current voltage.
[0092] In FIG. 5A, when a sine-wave-like alternate current voltage
of maximum voltage V.sub.0 with a predetermined frequency is
applied to the optical element 101 at time to, the interface of the
optical element 101 responds as a curve shown in FIG. 5B. That is,
the deformed amount starts with a predetermined time constant to
reach a value of 95% of the final deformed amount .delta.sine at
time t.sub.12 as in FIG. 4B. And as time lapses, the deformed
amount gets further closer toward .delta.sine, but subsequently
never decreases.
[0093] As described so far, the optical element 101 has different
response characteristics at the time of interfacial deformation
corresponding with driving frequency of the power supply means.
Under the circumstances, the one in which deformed response of the
interface 124 of the optical element 101 to frequencies of voltages
outputted from the power supply means is conceptually shown is FIG.
6. In the present drawing, the horizontal axis represents
frequencies of alternate current voltage supplied to the optical
element 101 by the power supply means while the vertical axis
represents deformation velocity of the interface at the time of
starting power supply, the interface deformed amount when
sufficient time has lapsed from the start of power supply, and
electric power which the power supply means consume.
[0094] According to the present drawing, the case of the driving
frequency of f.sub.1, which gives rise to the phenomena shown in
the above described FIG. 4B and cannot provide a predetermined
deformed amount, is inappropriate to control the optical state of
the optical element 101 exactly. The case of the driving frequency
of f.sub.2 can provide a predetermined deformed amount but
deformation (response) velocity is comparatively slow. The case of
the driving frequency of f.sub.3 can provide a predetermined
deformed amount and deformation velocity is fast. The case of the
driving frequency of f.sub.4 can no longer provide a predetermined
deformed amount. The reason hereof is that the optical element can
be regarded as a capacitance having a predetermined electrostatic
capacity, but since resistant of the transparent electrode 103 and
ion mobility of the electrolytic solution 122 are a limited values,
the driving frequency being a high frequency will prevent
electrical charge from being implanted into the optical element 101
so that the electric capillary phenomenon will not take place
effectively. That is, in order to control the optical element 101
effectively, it is necessary to appropriately set the electric
power supply condition for driving this.
[0095] FIG. 7 and FIGS. 8A to 8E are explanatory views related to
power supply means in the first embodiment of the present
invention, and FIG. 7 is a sectional view of the optical element of
this embodiment and a drawing to show a configuration of power
supply means.
[0096] In FIG. 7, reference numeral 130 denotes a central
processing unit (hereinafter to be referred to as CPU) to control
operation of a later-described optical apparatus 150 in its
entirety, and is one-chip microcomputer having ROM, RAM, EEPROM,
A/D converter function, D/A converter function, and PWM (Pulse
Width Modulation) function. Reference numeral 131 denotes power
supply means for applying voltages to the optical element 101, and
its configuration will be described as follows.
[0097] Reference numeral 132 denotes a direct current electric
power supply incorporated into the optical apparatus 150 such as a
dry cell, etc., reference numeral 133 denotes a DC/DC converter to
increase the voltage outputted from the electric power supply 132
to a desired voltage value corresponding with control signal of the
CPU 130, reference numerals 134 and 135 are amplifiers to amplify
in accordance with controlling signals of the CPU 130, for example,
frequency/duty ratio variable signals to be realized by PWM (Pulse
Width Modulation) function the signal levels to reach voltage
levels increased with the DC/DC converter. In addition, the
amplifier 134 is brought into connection with the transparent
electrode 103 of the optical element 101 and the amplifier 135 with
a stick-like electrode 125 of the optical element 101
respectively.
[0098] That is, corresponding with the controlling signals of the
CPU 130, output voltage of the electric power supply 132 will be
applied to the optical element 101 by the DC/DC converter 133, the
amplifier 134 and the amplifier 135 with a desired voltage value,
frequency and duty.
[0099] FIGS. 8A to 8E are explanatory views describing voltage
waveforms to be outputted from the amplifiers 134 and 135.
Incidentally, under assumption that a voltage of 100V was outputted
into the amplifiers 134 and 135 from the DC/DC converter 133
respectively, following description will be implemented.
[0100] As having been shown in FIG. 8A, the amplifiers 134 and 135
are respectively brought into connection with the optical elements
101. From the amplifier 134, as shown in FIG. 8B, a voltage of
rectangular waveform with desired frequency and duty ratio is
outputted by the controlling signals of the CPU 130. On the other
hand, from the amplifier 135, as having been shown in FIG. 8C, a
voltage of rectangular waveform with the opposite phase of the
amplifier 134, the same frequency and the same duty ratio is
outputted by the controlling signals of the CPU 130. This will
cause the voltage to be applied between the transparent electrode
103 and the sticklike electrode 125 of the optical element 101 to
become a rectangular waveform of .+-.100V, that is, an alternate
current voltage as shown in FIG. 8D.
[0101] Therefore, an alternate current voltage will be applied to
the optical element 101 with the power supply means 131.
[0102] In addition, an effective voltage applied to the optical
element from the application start of the voltage to be applied to
the optical element 101 can be show as in FIG. 8E.
[0103] Incidentally, in the above described description, a
rectangular waveform voltage was described to be outputted from the
amplifiers 134 and 135, but it goes without saying that likewise
configuration will be taken for sine waves.
[0104] In addition, in the above described description, the case
where the electric power supply 132 is incorporated into the
optical apparatus 150 was described, but the case where an exterior
type electric power supply or power supply means implement
alternate application into the optical element 101 will do as
well.
[0105] FIG. 9 is the one in which the optical element 101 was
applied to an optical apparatus. In this embodiment, the optical
apparatus 150 will be exemplified, for description, by so-called
digital still camera which converts a still image into electric
signals with photo-taking means and records them as digital
data.
[0106] Reference numeral 140 denotes a photo-taking optical system
comprising a plurality of lens groups and are configured by first
lens group 141, second lens group 142, and the optical element 101.
Forward and backward movement in the optical axis of the first lens
group 141 implements focus adjustment. The optical element 101
undergoes power change to implement zooming. Incidentally, in order
to implement zooming in the photo-taking optical system, normally
power changes in a plurality of lens groups and movement of the
groups are necessary, but for the present drawing, for the sake of
simplicity the power changes in the optical element 101 is caused
to represent the zooming operation. The second lens group 142 is a
relay lens group without movements. In addition, the optical
element 101 is disposed between the first lens group 141 and the
second lens group 142, and a diaphragm unit 143 to adjust the light
amount of photo-taking optical flux by adjusting diaphragm aperture
by a known art is disposed between the first lens group 141 and the
optical element 101.
[0107] In addition, the photo-taking means 144 is disposed in the
focal position (planned image forming surface) of the photo-taking
optical system 140. For this, photoelectric conversion means such
as a two-dimensional CCD, etc. comprising a plurality of
photoelectric conversion portions to convert the irradiated optical
energy into electrical charges, an electrical charge accumulating
portion to accumulate the electrical charges, and electrical charge
transfer portion to transfer the electrical charges and transmit
them to outside.
[0108] Reference numeral 145 denotes an image signal process
circuit, which brings the analog image signals inputted from the
photo-taking means 144 into A/D conversion, and implements image
processing such as AGC control, white balance, .gamma. correction,
and edge emphasis, etc.
[0109] Reference numeral 146 denotes a temperature sensor to
measure environmental temperature (air temperature) in the optical
apparatus 150.
[0110] Reference numeral 147 is a look-up table provided in the
memory region inside the CPU 130, and there duty ratio data on the
output voltage of the power supply means 131 necessary to control
the optical power of the optical element 101 at a predetermined
value are stored in a mode of a corresponding table.
[0111] Reference numeral 151 denotes a display such as a liquid
crystal display, etc., and displays the subject image recognized by
the photo-taking means 144 and the operation status of the optical
apparatus having a variable focal lens. Reference numeral 152
denotes a main switch to drive the CPU 130 from the sleeping state
to a state to execute the program while reference numeral 153
denotes a zoom switch, and corresponding with switch operation by
the photographer, the later described variable power operation is
implemented so that the focal length of the photo-taking optical
system 140 is changed. Reference numeral 154 is operation switches
other than the above described switches, which are configured by a
pre-photo-taking switch, photo-taking commencement switch, and a
photographic conditions setup switch to set up shutter timing by
second, etc.
[0112] Reference numeral 155 denotes focus detecting means and the
focus detecting means of phase difference detecting system, etc.
used for a single-lens reflex camera are suitable. Reference
numeral 156 denotes focusing operation means, which includes an
actuator and a driver circuit to move the first lens group 141
forward and backward in the optical axis, implements focus
operation based on the focus signals calculated by the above
described focus detecting means 155 so that the focus state of the
photo-taking optical system 140 is adjusted. Reference numeral 157
denotes memory means and the memory means records the photographed
image signals. In particular, a detachably attachable PC card type
flush memory, etc. are suitable.
[0113] FIG. 10 is a control flow chart on the CPU 130 which the
optical apparatus 150 having been shown in FIG. 9 has. The control
flow of the optical apparatus 150 will be described with reference
to FIG. 9 as well as FIG. 10 as follows.
[0114] In the step S101, distinction on whether or not on-operation
of the main switch 152 is executed is implemented and when the
on-operation is not yet executed, a waiting mode state in which
operation of various switches is waited for remains. In the step
S101, when on-switch operation of the main switch 152 is
distinguished, the waiting mode will be overridden and the process
continues to the subsequent step S102 and onward.
[0115] In the step S102, the ambient temperature where the optical
apparatus 150 is disposed, that is, the periphery air temperature
of the optical apparatus 150 is measured with the temperature
sensor 146.
[0116] In the step S103, setup of photographic conditions by a
photographer is accepted. For example, setup such as setup on
exposure control mode (shutter priority AE and program AE, etc.),
image quality mode (size in the number of recording pixels and size
of image compression rate, etc.), and the electronic flash mode
(compulsory flash and flash prohibition, etc.), etc. is
implemented.
[0117] In the step S104 distinction on whether or not the zoom
switch 153 has been operated by the photographer is implemented. In
the case no on-operation has been executed, the process continues
to the step S105. Here, in the case where the zoom switch 153 has
been operated, the process continues to the step S121.
[0118] In the step S121, the operation quantity of the zoom switch
153 (operation direction and on-time period, etc.) is detected. In
the step S122 the focal length control target value of the
photo-taking optical system 140 is calculated based on that
operation quantity. In the step S123 duty ratio on the voltage
applied to the optical element 101 corresponding to the above
described focal length control target value is read out from the
look-up table 147 in the CPU 130. The deformed amount of the
optical element 101 directed to the duty ratio will be described
later with reference to FIGS. 1A to 1C and FIGS. 11A to 1C. In the
step S124, power supply to the optical element 101 from the power
supply means 131 starts at the above described duty ratio, and the
state returns to the step S103.
[0119] That is, while operation of the zoom switch 153 goes on,
signals of a predetermined duty ratio corresponding with the
operation quantity are applied to the optical element 101 so that
the process continues to the step S105 at the time point when
on-operation of the zoom switch 153 is over.
[0120] In the step S105 distinction on whether or not on-operation
on the pre-photo-taking switch (indicated as SW1 in the flow chart
in FIG. 10) among the operation switches 154 has been executed by
the photographer is implemented. In the case where the on-operation
is not executed, the state returns to the step S103 so that
acceptance for setup of photographic conditions and distinguishing
on operation of zoom switch 153 is repeated. Once the
pre-photo-taking switch is determined to have been operated on in
the step S105, the process continues on to the step S111.
[0121] In the step S111, the photo-taking means 144 as well as the
signal process circuit 145 is driven to acquire the preview image.
The preview image refers to an image to be acquired prior to
photo-taking session in order to appropriately set up the
photo-taking conditions on the image for final recording as well as
to make the photographer understand the photo-taking
construction.
[0122] In the step S112 the received light level of the preview
image acquired by the step S111 is recognized. In particular, in
the image signals which the photo-taking means 144 output, the
output signal levels of maximum, minimum and average are calculated
so that the light amount emitted into the photo-taking means 144 is
precieved.
[0123] In the step S113, based on the received light amount
recognized on the above described step S112, the diaphragm unit 143
provided within the photo-taking optical system 140 is driven so
that the aperture diameter of the diaphragm unit 143 is adjusted so
as to be a proper light amount.
[0124] In the step S114, the preview image acquired in the step
S111 is displayed in the display 151. Subsequently, in the step
S115, with the focus detecting means 155 the focus state of the
photo-taking optical system 140 is detected. Subsequently, in the
step S116, with the focus drive means 156, the first lens group 141
is caused to move forward and backward toward the optical axis to
implement accurate focusing operation. Thereafter, the process
continues to the step S117 to distinguish whether or not the
on-operation of the photo-taking switch (which is expressed as SW2
in the flow chart FIG. 10) has been implemented. When it does not
undergo on-operation, the state goes back to the step S111 and the
steps covering from the acquisition of the preview image to the
focus drive is repeatedly executed. As described above, in the
midst of executing the pre-photo-taking operation repeatedly, the
photographer could implement on-operation of the photo-taking
switch, and then the state leaps from the step S117 to the step
S131.
[0125] In the step S131, photo-taking session is implemented. That
is, the subject image formed on the photo-taking means 144
undergoes photoelectric conversion, and the electrical charges in
proportion to intensity of the optical image are accumulated in the
electrical charge accumulating portion in the vicinity of each
light receiving portion. In the step S132 the electrical charges
accumulated in the step S131 is read out via accumulated electrical
charge transfer line, and the read-out analog signals are inputted
into the signal process circuit 145. In the step S133, in the
signal process circuit 145, the analog image signals are inputted
into A/D conversion, and implements image processing such as AGC
control, white balance, .gamma. correction, and edge emphasis, etc.
are implemented, and moreover if there arises any necessity, JPEG
compression, etc. is implemented with image compression program
stored inside the CPU 130. In the step S134 the image signals
acquired in the above described step S133 are recorded into the
memory 157. In the step S135 at first the preview image displayed
in the step S114 is erased, and the image signals acquired in the
step S133 is again displayed on the display 151. In the step S136
power supply outputs from the power supply means 131 is stopped so
that a series of photo-taking operations come to an end in the step
137.
[0126] Next, actions in the step S123 in the above described FIG.
10 will be described with reference to FIGS. 1A to 1C and FIGS. 11A
to 11C. FIGS. 11A to 11C are explanatory views describing control
method of the power supply means and its effects in the case where
the interface 124 of the optical element 101 is deformed
significantly and the focal length of the optical element 101 is
made short.
[0127] FIG. 11A shows voltage waveform outputted from the power
supply means 131 and applied to the optical element 101, and its
definition is similar to the one having been described in FIG. 8D.
This waveform represents an alternate current voltage of a
rectangular wave with the peak voltage of .+-.V.sub.0 [V],
frequency of 1 kHz, and duty ratio of 100%. At this time, the
effective voltage applied to the optical element 101 will be
V.sub.0 as in FIG. 11B and deformation of the interface 124 will
get still with a predetermined deformation amount .delta..sub.1 as
shown in FIG. 11C.
[0128] FIGS. 1A to 1C are explanatory views describing control
method of the power supply means and its effects in the case where
deformation amount given to the interface 124 of the optical
element 101 is smaller than in FIG. 11.
[0129] FIG. 1A shows a voltage waveform outputted from the power
supply means 131 and applied to the optical element 101. This
waveform represents an alternate current voltage of a rectangular
wave with the peak voltage of .+-.V.sub.0 [V] similar to that in
FIG. 11, frequency of likewise 1 kHz, and duty ratio of 50%. At
this time, the effective voltage applied to the optical element 101
will be 0.5 V.sub.0 as in FIG. 1B and deformation of the interface
124 will get still with approximately half the deformation amount
as shown in FIG. 11, that is, 0.5.delta..sub.1.
[0130] That is, in this embodiment, the peak voltage and the
frequency of the drive voltage outputted from the power supply
means are always constant, and the duty ratio is made variable so
that the effective voltage to be supplied to the optical element
101 is controlled and the deformation amount of the interface 124
is controlled. In addition, 1 kHz was taken for this drive
frequency in this embodiment, but this is equivalent to the
frequency in the vicinity of f.sub.3 in FIG. 6. Selection of such a
frequency enables the optical power of the optical element 101 to
change rapidly and stably.
[0131] According to the above described first embodiment:
[0132] (1) The peak voltage and the frequency of the drive voltage
outputted from the power supply means are made to be constant, and
only the duty ratio is made variable results in simple
configuration of the power supply means and can provide with power
supply means suitable to digital control with a microcomputer, etc.
As a result thereof, optical characteristics of an optical element
will become accurately controllable with an inexpensive control
circuit; and,
[0133] (2) Since the output frequency of the power supply means has
been selected to be higher than the frequency with which electrical
charge implantation into the insulating layer of the optical
element takes place and to be lower than the frequency with which
electrical charge movements due to increase in impedance are
hampered, the interface can be deformed on a stable basis, and the
like will be attained.
[0134] Incidentally, in this embodiment, as an example of the
optical element, a digital still camera which brings images into
photoelectric conversion and records those data was taken, but it
goes without saying that also a video camera or a silver halide
film camera recording images into a silver halide film, etc. can be
taken likewise without spoiling the effects.
[0135] [Second Embodiment]
[0136] The above described first embodiment was a mode of
embodiment in which an alternate voltage with the peak voltage and
the frequency being constant was applied to the optical element and
duty of the alternate signals is changed so that the interface of
the optical element was deformed into a desired shape. In contrast
hereto, as the second embodiment, an embodiment in which an
alternate current voltage with the peak voltage and duty being
constant is applied to an optical element, and variation of
frequency of that alternate signals deforms the interface of the
optical element into a desired shape will be shown.
[0137] FIG. 12 through FIGS. 15A to 15C are drawings to describe
this embodiment, and FIG. 12 is a drawing to show configuration of
a optical element of this embodiment, or a drawing to show a
digital still camera 250 comprising the optical element 101 and the
power supply means 131 as in the first embodiment.
[0138] A portion which differentiates the optical element 250 of
this embodiment from the optical element 150 of the first
embodiment is a point that the CPU 230 has a look-up table 247
which stores output frequency data of the power supply means 131
necessary for controlling the optical power of the optical element
101 at a predetermined value in a mode of a corresponding table.
Otherwise, the configuration and effects are similar to those in
the first embodiment and therefore detailed description will be
omitted.
[0139] FIG. 13 is a control flow chart on the CPU 230 which the
optical apparatus 250 in the second embodiment has. A portion which
differentiates the present flow chart from the flow chart in FIG.
10 in the first embodiment is only the portion to readout data from
the above described look-up table 247. This altered portion only
will be described as follows.
[0140] In the step S204 distinction on whether or not the zoom
switch 153 has been operated by the photographer is implemented,
and in the case where the zoom switch 153 has been operated, the
process continues to the step S221.
[0141] In the step S221, the operation quantity of the zoom switch
153 (operation direction and on-time period, etc.) is detected. In
the step S222 the focal length control target value of the
photo-taking optical system 140 is calculated based on that
operation quantity. In the step S223 frequency on the power supply
signals applied to the optical element 101 corresponding to the
above described focal length control target value are read out from
the look-up table 127 in the CPU 230. The deformed amount of the
optical element 101 directed to the frequency will be described
with reference to FIG. 14 and FIG. 15. In the step S224, power
supply to the optical element 101 from the power supply means 131
starts at the above described frequency, and the state returns to
the step S203.
[0142] Next, actions in the step S223 in the above described FIG.
13 will be described with reference to FIGS. 14A to 14C and FIGS.
15A to 15C. FIGS. 14A to 14C are explanatory views describing
control method of the power supply means and its effects in the
case where the interface 124 of the optical element 101 is deformed
significantly and the focal length of the optical element 101 is
made short.
[0143] FIG. 14A shows voltage waveform outputted from the power
supply means 131 and applied to the optical element 101, and its
definition is similar to the one having been described in FIG. 8D
or FIG. 1A and FIG. 11A. This waveform represents an alternate
voltage of a rectangular wave with the peak voltage of .+-.V.sub.0
[V], frequency of 2 kHz, and duty ratio of 100%. At this time, the
effective voltage applied to the optical element 101 will be
V.sub.0 as in FIG. 11B and deformation of the interface 124 will
get still with a predetermined deformation amount .delta..sub.2 as
shown in FIG. 11C.
[0144] FIGS. 15A to 15C are explanatory views describing control
method of the power supply means and its effects in the case where
deformation amount given to the interface 124 of the optical
element 101 is smaller than in FIGS. 14A to 14C.
[0145] The above described FIG. 15A shows a voltage waveform
outputted from the power supply means 131 and applied to the
optical element 101. This waveform represents an alternate voltage
of a rectangular wave with the peak voltage of .+-.V.sub.0 [V]
similar to that in FIGS. 14A to 14C, duty ratio of likewise 100%,
and frequency of 4 kHz being a double. At this time, the effective
voltage applied to the optical element 101 will be V.sub.0 as in
FIG. 14B and deformation of the interface 124 will as shown in FIG.
15C get still with approximately half the deformation amount in
FIGS. 14A to 14C, that is, 0.5.delta..sub.2.
[0146] This is caused by this embodiment's adoption of frequency in
the vicinity of f.sub.4 in FIG. 6. That is, this is caused since
with the power supply voltage having frequency higher than a
predetermined value, electrical charges for deforming the interface
124 can no longer be supplied to the optical element 101 easily,
and occurrence of the electric capillary phenomenon is controlled.
Accordingly, since the deformation amount of the interface 124
decreases as the drive frequency increases, control on the drive
frequency can control the optical power of the optical element 101
at a predetermined value According to the above described second
embodiment:
[0147] (1) The peak voltage and the duty ratio of the drive voltage
outputted from the power supply means are made to be constant, and
only the frequency is made variable results in simple configuration
of the power supply means and can provide with control means
suitable to digital control with a microcomputer, etc. As a result
thereof, optical characteristics of an optical element will become
accurately controllable with an inexpensive control circuit;
and,
[0148] (2) Since the output frequency of the power supply means has
been selected to be a frequency higher than the frequency with
which electrical charge movements into the optical element are
hampered, the interface can be deformed accurately and continuously
by changes in frequency, and the like will be attained.
[0149] Incidentally, also in this embodiment, as an example of the
optical element, a digital still camera was taken, but it goes
without saying that also a video camera or a silver halide film
camera, etc. other than that can be taken likewise without spoiling
the effects.
[0150] [Third Embodiment]
[0151] FIG. 16 through FIGS. 21A to 21D are drawings to describe
the third embodiment of the present invention, and FIG. 16 and
FIGS. 17A and 17B are drawings related to an optical element and
power supply means to be used in this embodiment.
[0152] FIG. 16 is a sectional view to show configuration of a
optical element of this embodiment, and a drawing to show
configuration of the power supply means to drive this. With
reference to FIG. 16, configuration of the optical element will be
described.
[0153] In FIG. 16, reference numeral 801 denotes the optical
element in its entirety, and reference numeral 802 denotes a
disk-like transparent acryl or glass-made first sealing plate.
[0154] Reference numeral 803 denotes an electrode ring, and size of
its outer diameter is unanimous while the size of its inner
diameter gradually changes in the downward direction. That is, in
this embodiment, it is a metal ring member the diameter of which
gets gradually larger in the downward direction on the size of
inner diameter. An insulating layer 804 made of acryl resin, etc.
is formed in tight contact with the inner face of the whole
periphery of the electrode ring 803. Since the inner size of the
insulating layer 804 is unanimous, thickness gradually increases in
the downward direction. In addition, to the bottom side of the
inner face of the whole periphery of the insulating layer 804, a
water-repelling treatment agent is applied so that a
water-repelling film 811 is formed and to the upper side of the
inner face of the whole periphery of the insulating layer 804, a
hydrophilic treatment agent is applied so that a hydrophilic film
812 is formed.
[0155] Reference numeral 806 is a disk-like transparent acryl-made
or glass-made second sealing place, and a through-hole is opened in
a portion thereof, and there a stick-like electrode 825 is inserted
and sealed with an adhesive agent.
[0156] Reference numeral 807 denotes a diaphragm plate to regulate
the diameter of an optical flux to be emitted into the optical
element 801, and is fixed-disposed on the upper surface of the
second sealing plate 806. In addition, the first sealing plate 802,
the metal ring 803 and the second sealing plate 806 are fixed each
other by adhesive treatment, and a box having a sealed space in a
predetermined volume enclosed by these members, or a liquid chamber
is formed. This box is shaped axially symmetric with respect to
light axis 823 other than the portion where the above described
stick-like electrode 825 is inserted. In addition, the liquid
chamber is filled with two kinds of liquid described below.
[0157] At first, on the bottom side of the liquid chamber, the
second liquid 822 is dropped with only a quantity so that the
height of its liquid pole reaches the same height as the forming
portion of the above described water-repelling film 811. As the
second liquid 822 silicone oil which is colorless and transparent
with specific gravity 1.06, refractive index of 1.38 is used.
Subsequently, the remaining space inside the liquid chamber is
filled with the first liquid 821. The first liquid 821 is
electrolytic solution, which is a mixture of water and
ethyl-alcohol at a predetermined ratio and moreover to which a
predetermined quantity of salt (sodium chloride etc.) is added,
with specific gravity 1.06 and with refractive index 1.38 under a
room temperature. Moreover, to the first liquid 821, uncolored
water-soluble dye, for example, carbon black or materials in the
titan oxide system are added. That is, for the first and the second
liquid, liquids which have the same specific gravity and refractive
index but have different light beam absorptive powers and are
insoluble each other are selected. There, the both liquids form an
interface 824 and each of them exists independently without being
mixed together. In addition, the shape of this interface 824 is
determined by the point where three substances of the inner wall of
the liquid chamber, the first liquid and the second liquid are
brought into intersection, that is, the balance of three
interfacial tensions applied to the outer periphery portion of the
interface 824. In this embodiment, the materials for the above
described water-repelling film 811 as well as hydrophilic film 812
are selected so that the contact angle of the first and the second
liquids toward the inner wall of the liquid chamber is 90 degrees
respectively.
[0158] Since reference numeral 131 denotes a member having the same
configuration as well as function as in the power supply means
described in FIGS. 1A to 1C, detailed description will be omitted.
The amplifier 134 of the power supply means 131 is brought into
connection with the metal ring 803 and the amplifier 135 with a
stick-like electrode 825. In this configuration, voltages are
applied to the first liquid 821 via the stick-like electrode 825
and the interface 824 is deformed by electro-wetting effects.
[0159] Next, deformation of the above described interface 824 of
the optical element 801 and the optical function given rise to by
the deformation will be described with reference to FIGS. 17A and
17B.
[0160] At first, in the case where no voltages are applied to the
first liquid 821, the shape of the interface 824 will be flat as
described above (FIG. 17A).
[0161] Here, the second liquid is practically transparent, but the
first liquid has a predetermined light beam absorptive power due to
an added light absorbing material. There, when a light flux is
emitted in from the opening of the diaphragm plate 807, the light
beam equivalent to the light length of the first liquid is absorbed
and the intensity of the light flux emitted out from the second
sealing plate 802 decreases uniformly.
[0162] On the other hand, when voltages are applied to the first
liquid, the shape of the interface 824 will become spherical due to
electro-wetting effects (FIG. 17B). There, on the light flux
emitted in from the opening of the diaphragm plate 807, the
absorption rate changes at a percentage corresponding with changes
in the light length in the first liquid, and the intensity of the
light flux emitted out from the second sealing plate 802 gradually
decreases in the direction from the center toward the periphery
with its average intensity being higher than in the case of FIG.
17A. That is, deformation of the interface 824 by the voltage
control of the power supply means 131 can realize an optical
element which can freely change the transmitting light amount.
[0163] In addition, since the refractive indexes for the first and
the second liquids are the same and only intensity of the emitted
light can be changed without changing the direction of the incident
light flux, the element can be used as a diaphragm means to adjust
light amount of the incident light flux or an optical shutter to
transmit or cut the incident light flux.
[0164] Incidentally, principles on the two-liquid interfacial
deformation due to electro-wetting is described in the above
described international patent WO99/18456, and the interface 824 in
this embodiment is equivalent to the positions A and B of the
two-liquid interface described in FIG. 6 of the above described
patent. In addition, principles on the transmitting light amount
adjustment of the incident light flux due to deformation of
two-liquid interface and its effects are described in Japanese
Patent Application Laid-Open No. 11-169657 made by the present
applicant.
[0165] FIG. 18 is the one in which the optical element 801 was
applied to an optical apparatus. In this embodiment, as in the
first embodiment, the optical apparatus 150 will be exemplified,
for description, by so-called digital still camera which converts a
still image into electric signals with photo-taking means and
records them as digital data. Incidentally, as for those similar to
the ones in the first embodiment, detailed description thereon will
be omitted.
[0166] In FIG. 18, reference numeral 430 denotes a photo-taking
optical system comprising a plurality of lens groups and are
configured by first lens group 431, second lens group 432, and the
forth lens group 433. Forward and backward movement in the optical
axis of the first lens group 431 implements focus adjustment.
Forward and backward movement in the optical axis of the second
lens group 432 implements zooming. The fourth lens group 433 is a
relay lens group without movement. In addition, an optical element
801 is disposed between the second lens group 432 and the fourth
lens group 433. In addition, the photo-taking means 144 is disposed
in the focusing position (planned image forming surface) of the
photo-taking optical system 430.
[0167] Next, operation of the optical element 801 in this
embodiment will be described.
[0168] Dynamic range of luminance of subjects existing in the
natural world is extremely large, and in order to limit this within
a predetermined range, normally the interior of the photo-taking
optical system has a mechanical diaphragm mechanism to adjust light
amount of the photo-taking light flux. However, it is difficult to
make the mechanical diaphragm mechanism small, and under a state of
small diaphragm that the diaphragm opening is small, diffraction
phenomena of the light beam due to end surface of diaphragm wings
occurs and, the resolution of the subject image decreases. Thus, in
this embodiment, the optical element 801 is used as a variable ND
filter replacing the above described mechanical diaphragm mechanism
so that without giving rise to the above described defects, the
light amount passing through the photo-taking optical system is
adjusted appropriately.
[0169] FIG. 19 is a control flow chart on the CPU 330 which the
optical apparatus 350 having been shown in FIG. 18 has. The control
flow of the optical apparatus 350 will be described with reference
to FIG. 18 as well as FIG. 19 as follows. Incidentally, as for the
control flow similar to that in the first embodiment, detailed
description thereof will be omitted.
[0170] In the step S301, distinction on whether or not on-operation
of the main switch 152 is executed by the photographer is
implemented and when the on-operation is not yet executed, the
state remains in the step S301. In the step S301, when on-switch
operation of the main switch 152 is distinguished, the CPU 330 gets
out of the sleep state so as to execute the step S302 and
onward.
[0171] In the step S302, as in the first embodiment, the ambient
temperature where the optical apparatus 350 is disposed, that is,
the periphery air temperature of the optical apparatus 350 is
measured with the temperature sensor 146.
[0172] In the step S303 setup of photographic conditions by a
photographer is accepted.
[0173] Inthe step S304 distinction on whether or not on-operation
on the pre-photo-taking switch (indicated as SW1 in the flow chart)
has been executed by the photographer is implemented. In the case
where the on-operation is not executed, the state returns to S303
so that distinguishing on acceptance for setup of photographic
conditions is repeated.
[0174] Once the pre-photo-taking switch is determined to have been
operated on in the step S304, the process continues to the step
S311.
[0175] Since the step S311 as well as the step S312 is similar to
those in the first embodiment, description thereon will be
omitted.
[0176] In the step S313 distinction on whether or not the received
light amount judged in the above described step S312 is appropriate
is implemented. In addition, when the present step recognizes its
appropriateness, the process continues to the step S314.
[0177] On the other hand, when in the step S313 it is distinguished
that the received light amount judged in the above described step
S312 is not appropriate, the state leaps to the step S321. In the
step S321 the actual received light amount is compared with the
appropriate received light amount so as to calculate the
appropriate transmittance to be given to the optical element 801
inside the photo-taking optical system 430. In the step S322 the
voltage to be applied to the optical element 801 is calculated in
order to acquire the appropriate transmittance calculated in the
step S321. In particular, the ROM of the CPU 330 stores the
relationship on the transmittance toward the applied voltage as the
form of look-up table 347, the applied voltage V.sub.3 directed to
the transmittance calculated in the step S321 is acquired with
reference to the table. That is, in order to control the
interfacial deformation amount of the optical element, the duty
ratio of the alternate output from the power supply means in the
first embodiment and the frequency in the second embodiment were
switched, but in the third embodiment, the peak voltage is
switched.
[0178] In the step S323, the power supply means apply to the
optical element 801 an alternate current voltage with the peak
voltage of .+-.V.sub.3 and the first frequency. Here, in this
embodiment, the first frequency is set at 1 kHz. Then, the
interface 824 of the optical element 801 is deformed into a
predetermined shape corresponding with the effective value of the
input voltage, and the light flux transmittance of the element 801
is controlled at the desired value.
[0179] After execution of the step S323, the state returns to the
step S311, and until the incident light amount into the
photo-taking means 144 becomes appropriate, the steps from image
signals acquisition in the step S311 to the step 323 are executed
repeatedly. In addition, when the incident light amount into the
photo-taking means 144 becomes appropriate, the state shifts from
the step S313 to the step S314.
[0180] In the step S314, the frequency of the alternate signals
outputted from the power supply means 131 is switched with the
second frequency. In this embodiment, the second frequency is set
at 250 Hz, but effects due to this switching will be described with
reference to FIG. 20 and FIG. 21 later.
[0181] In the step S315, the preview image acquired in the step
S311 is displayed in the display 151. Subsequently, in the step
S316, with the focus detecting means 155 the focus state of the
photo-taking optical system 430 is detected. Subsequently, in the
step S317, with the focus drive means 156, the first lens group 431
is caused to move forward and backward toward the optical axis to
implement accurate focusing operation. Thereafter, the process
continues to the step S318 to distinguish whether or not the
on-operation of the photo-taking switch (which is expressed as SW2
in the flow chart FIG. 19) has been implemented. When it does not
undergo on-operation, the state goes back to the step S311 and the
steps covering from the acquisition of the preview image to the
focus drive is repeatedly executed.
[0182] As described above, if in the midst of executing the
pre-photo-taking operation repeatedly, the photographer implements
on-operation of the photo-taking switch, and then the state leaps
from the step S318 to the step S331. In the step S331, the
frequency of the alternate signals outputted form the power supply
means 131 is switched with the first frequency. That is, the
frequency is made to get back to 1 kHz from 250 Hz.
[0183] In the step S332, photo-taking session is implemented. That
is, the subject image having been formed on the photo-taking means
144 undergoes photoelectric conversion, and the electrical charges
in proportion to intensity of the optical image are accumulated in
the electrical charge accumulating portion in the vicinity of each
light receiving portion. In the step S333 the electrical charges
accumulated in the step S131 are read out via accumulated
electrical charge transfer line, and the read-out analog signals
are inputted into the signal process circuit 145. In the step S334,
in the signal process circuit 145, the analog image signals are
inputted into A/D conversion, and image processing such as AGC
control, white balance, .gamma. correction, and edge emphasis, etc.
are executed, and moreover if there arises any necessity, JPEG
compression, etc. is implemented with image compression program
stored inside the CPU 330. In the step S335 the image signals
acquired in the above described step S334 are recorded into the
memory 157. In the step S336 at first the preview image displayed
in the step S315 is erased, and the image signals acquired in the
step S334 is again displayed on the display 151. In the step S337
power supply outputs from the power supply means 131 is stopped so
that a series of photo-taking operations come to an end in the step
338.
[0184] Next, influence and effects in switching of the frequency of
the power supply means output will be described with reference to
FIGS. 20A to 20D and FIGS. 21A to 21D. FIG. 20 is explanatory views
describing control method of the power supply means and its effects
in the case where the output of the power supply means 131 is with
the first frequency, that is, 1 kHz.
[0185] FIG. 20A shows voltage waveform outputted from the power
supply means 131 and applied to the optical element 101, and its
definition is similar to the one having been described in FIG. 8D.
This waveform represents an alternate current voltage of a
rectangular wave with the peak voltage of .+-.V.sub.3 [V],
frequency of 1 kHz, and duty ratio of 100%. The frequency 1 kHz
here is equivalent to f.sub.3 in FIG. 6. At this time, the
effective voltage applied to the optical element 101 will be
V.sub.3 as in FIG. 20B, and the electric power consumption in the
power supply means 131 will be shown in FIG. 20C. That is, since
the optical element 801 is structured as a capacitor, after
application of a constant voltage, in-flow current decreases as
electrical charges are accumulated, and therefore, the electric
power consumption repeats minute variations in synchronization with
switching on polarity of the voltage of the electric power supply
as shown in FIG. 20C. The peak value of the electric power
consumption at this time is assumed to be W30 and the average value
to be W31 respectively. In addition, the interface 824 is deformed
with waveform shown in FIG. 20D.
[0186] FIGS. 21A to 21D are explanatory views describing control
method of the power supply means and its effects in the case where
the output of the power supply means 131 is with the second
frequency, that is, 250 kHz, and respective waveforms constitute
the same meaning as in FIGS. 20A to 20D.
[0187] FIG. 21A shows voltage waveform outputted from the power
supply means 131 and applied to the optical element 101, and is an
alternate current voltage of a rectangular wave with the peak
voltage of .+-.V.sub.3 [V] the same as in FIGS. 20A to 20D, and
duty ratio of 100% also the same as in FIGS. 20A to 20D while the
frequency is 250 Hz. The frequency 250 Hz here is equivalent to
f.sub.2 in FIG. 6. At this time, the effective voltage applied to
the optical element 101 will be V.sub.3 as in FIG. 21B, and the
electric power consumption in the power supply means 131 will be
shown in FIG. 21C. That is, since the frequency of the signals of
power supply to the optical element 801 has decreased, the electric
power consumption varies more significantly than that having been
shown in FIG. 20C. Accordingly, the electric power consumption
average value W.sub.32 is lower than in the case of FIGS. 20A to
20D. In addition, the interface 824 is deformed with waveform shown
in FIG. 21D, but the interfacial deformation velocity at this time
is slower than in the case of FIG. 20D. However, after the
interfacial deformation amount becomes still with a predetermined
value .delta.3, the interfacial shape gets stable.
[0188] According to descriptions so far, with alternate signals
with high frequencies to be applied to the optical element 801, the
electric power consumption gets larger but the response velocity of
the interface gets faster while with the signals with low
frequencies the response gets slower but the electric power
consumption may be less. Accordingly, in this embodiment, as having
been shown in the step S323 in FIG. 19, in the case where the
interface shape of the optical element is deformed, application of
high frequency makes swift deformation possible. On the other hand,
as having been shown in the step S314 in FIG. 19, in the case where
deformation comes to an end and a predetermined shape is
maintained, the drive frequency is switched to a low frequency so
as to attain power saving. In this case, deformation of the
interface 824 is already over, and therefore slowness in response
velocity of the interface will not become any obstacle.
[0189] In addition, in this embodiment, as having been shown in the
step S331 in FIG. 19, immediately prior to photo-taking operation,
the drive frequency is caused to get back to a high frequency. This
serves to strengthen the interface constraint power of the optical
element at the time of a photo-taking session, and reduce variation
in optical characteristics due to external disturbances during a
photo-taking session. In addition, since photo-taking time period
is short, increase in electric power consumption will not become
any serious obstacles.
[0190] According to the above described third embodiment:
[0191] (1) The frequency of the drive signals outputted from the
power supply means are switched appropriately corresponding with
the state of the optical apparatus so that without sacrificing the
deformation velocity of the optical element energy saving on the
power supply means can be planned; and,
[0192] (2) At the time when high stability is required in the
optical element a high frequency drive signal is supplied and at
the time when low stability is tolerable a low frequency drive
signal is supplied so that without reducing performance of the
optical apparatus energy saving on the power supply means can be
planned, and the like will be attained.
[0193] Incidentally, in this embodiment, as an example of the
optical element, a digital still camera was taken, but it goes
without saying that also a video camera or a silver halide film
camera, etc. other than that can be taken likewise without spoiling
the effects. In addition, the power supply control method of the
optical element 801 of this embodiment may be applied to the first
embodiment and the second embodiment to attain similar effects, and
the power supply control method of the first embodiment and the
second embodiment may be applied to the third embodiment to attain
similar effects.
[0194] [Fourth Embodiment]
[0195] FIG. 22 shows another example in which the optical element
101 shown in FIG. 2 has been applied to an optical apparatus. In
this embodiment, the same symbols are given for the same
configuration as in the configuration having been shown in FIG. 9.
A timer 147' provided in the CPU 130 is provided to this
embodiment, and time set by the CPU 130 is counted.
[0196] FIG. 23 is a control flow chart of the CPU 130 which the
optical apparatus 150 having been shown in FIG. 22 has. The control
flow of the optical apparatus 150 will be described with reference
to FIG. 22 as well as FIG. 23 as follows.
[0197] In the step S1101, distinction on whether or not
on-operation of the main switch 152 is executed is implemented and
when the on-operation is not yet executed, a waiting mode state in
which operation of various switches is waited for remains. In the
step S1101, when on-switch operation of the main switch 152 is
distinguished, the waiting mode will be overridden and thereafter
the process continues to the subsequent step S1102.
[0198] In the step S1102, the ambient temperature where the optical
apparatus 150 is disposed, that is, the periphery air temperature
of the optical apparatus 150 is measured with the temperature
sensor 146.
[0199] In the step S1103 setup of photographic conditions by a
photographer is accepted. For example, setup such as setup on
exposure control mode (shutter priority AE and program AE, etc.),
image quality mode (size in the number of recording pixels and size
of image compression rate, etc.), and the electronic flash mode
(compulsory flash and flash prohibition, etc.), etc. is
implemented.
[0200] In the step S1104 distinction on whether or not the zoom
switch 153 has been operated by the photographer is implemented. In
the case no on-operation has been executed, the process continues
to the step S1105. Here, in the case where the zoom switch 153 has
been operated, the process continues to the step S1121.
[0201] In the step S1121 distinction on whether or not the timer
147' is in the midst of counting is implemented. If counting is not
going on, the process continues to the step S1123, and in the case
where counting is going on, after resetting the counter value
(S1122), the state continues to the step S1123.
[0202] In the step S1123, the operation quantity of the zoom switch
153 (operation direction and on-time period, etc.) is detected, and
the corresponding varied amount of focal length is calculated based
on that operate amount (S1124). As the result of that calculation,
the reference voltage value to be applied finally V.sub.0 to the
optical element 101 is determined (S1125), and the process
continues to the subroutine of "temperature correction" to correct
standard voltage value to be applied finally in terms of
temperature and decide the waveform of applying voltage (the
details will be described later). The power supply means 131 are
controlled with the corrected finally applying voltage value and
applying waveform pattern to be applied to the optical element 101
decided in the subroutine so that a voltage is applied to the
optical element (S1127). Concurrently therewith, counting of the
timer 147' is started (S1128). And the state goes back to the step
S1103. That is, in the case where operation of the zoom switch 153
goes on, the step S1103 to the step S1128 are repeatedly executed
so that the process continues to the step S1105 at the time point
when on-operation of the zoom switch 153 is over.
[0203] In the step S1105 distinction on whether or not on-operation
on the pre-photo-taking switch (indicated as SW1 in the flow chart
in FIG. 23) among the operation switches 154 has been executed by
the photographer is implemented. In the case where the on-operation
is not executed, the state returns to the step S1103 so that
acceptance for setup of photographic conditions and distinguishing
on operation of zoom switch 153 are repeated. Once the
pre-photo-taking switch is determined to have been operated on in
the step S1105, the process continues to the step S1111.
[0204] In the step S1111, the photo-taking means 144 as well as the
signal process circuit 145 is driven to acquire the preview image.
The preview image refers to an image to be acquired prior to
photo-taking session in order to appropriately set up the
photo-taking conditions on the image for final recording as well as
to make the photographer understand the photo-taking
construction.
[0205] In the step S1112 the received light level of the preview
image acquired by the step S1111 is recognized. In particular, in
the image signals which the photo-taking means 144 output, the
output signal levels of maximum, minimum and average are calculated
so that the light amount emitted into the photo-taking means 144 is
precieved.
[0206] In the step S1113, based on the received light amount
recognized by the above described step S1112, the aperture stop
unit 143 provided in the photo-taking optical system 140 is driven
so that the aperture diameter of the aperture stop unit 143 is
adjusted so as to obtain a proper light amount.
[0207] In the step S1114, the preview image acquired in the step
S1111 is displayed in the display 151. Subsequently, in the step
S1115, with the focus detecting means 155 the focus state of the
photo-taking optical system 140 is detected. Subsequently, in the
step S1116, with the focus drive means 156, the first lens group
141 is caused to move forward and backward toward the optical axis
to implement accurate focusing operation. Thereafter, the process
continues to the step S1117 to distinguish whether or not the
on-operation of the photo-taking switch (which is expressed as SW2
in the flow chart FIG. 23) has been implemented. When it does not
undergo on-operation, the state goes back to the step S1111 and the
steps covering from the acquisition of the preview image to the
focus drive is repeatedly executed.
[0208] As described above, if in the midst of executing the
pre-photo-taking operation repeatedly, when the photographer
implements on-operation of the photo-taking switch, whether or not
counting of the timer 147' is completed is distinguished (S1118).
In the case where counting is not yet completed, distinction will
go on as is, and at the time point when counting of the timer 147'
is completed, the state leaps from the step S1118 to the step
S1131, and after the counted value of the timer 147' is reset
(S1131), the process continues to the step S1132.
[0209] In the step S1132, photo-taking session is implemented. That
is, the subject image having been formed on the photo-taking means
144 undergoes photoelectric conversion, and the electrical charges
in proportion to intensity of the optical image are accumulated in
the electrical charge accumulating portion in the vicinity of each
light receiving portion. In the step S1133 the electrical charges
accumulated in the step S132 are read out via accumulated
electrical charge transfer line, and the read-out analog signals
are inputted into the signal process circuit 145. In the step
S1134, in the signal process circuit 145, the analog image signals
are inputted into A/D conversion, and image processing such as AGC
control, white balance, y correction, and edge emphasis, etc. are
implemented, and moreover if there arises any necessity, JPEG
compression, etc. is implemented with image compression program
stored inside the CPU 130. In the step S1135 the image signals
acquired in the above described step S1134 are recorded into the
memory 157, and at the same time, in the step S1136 the preview
image is erased once, and afterwards the image signals acquired in
the step S1134 is again displayed on the display 151. Thereafter,
the power supply means 131 is controlled to stop voltage
application to the optical element 101 (S1137) so that a series of
photo-taking operations come to an end.
[0210] Next, the case where temperature correction is implemented
will be described with reference to FIG. 24 and FIGS. 25A to 25D.
In the step S1151 distinction on whether or not the air temperature
measured with the temperature sensor 146 is not less than
15.degree. C. is implemented. In the case where the air temperature
is not more than 15.degree. C., the waveform of applying voltage A
having been shown in FIG. 25A is selected (S1152). At the time of
low temperature, viscosity of the liquids 121 and 122 in the
optical element 101 becomes high to lengthen the time period until
the interface completes deformation, and therefore by applying
voltage higher than a predetermined final voltage reference value
V.sub.0 at the startup after the electric power supply is switched
on, the interfacial deformation amount at the time of startup is
made to increase so that the completion time period of the
interfacial deformation is planned to be short.
[0211] In this waveform pattern, for a predetermined time period
prior to the first voltage to be applied to the optical element
101, that is, the final voltage reference value V.sub.0 is applied
(hereinafter to be referred to as pre-applying time), the second
voltage higher than the final voltage reference value V.sub.0, that
is, the prevoltage value V.sub.1 is applied to the optical element
101, and after the pre-applying time lapses the final voltage
reference value V.sub.0 is applied to the optical element 101.
[0212] In the case where the measured air temperature is not less
than 10.degree. C. and less than 15.degree. C. (S1153), the
pre-applying time is set at 0 ms (S1154), and the process continues
to the S1180 where the prevoltage value V.sub.1 is calculated.
[0213] In the case where the measured air temperature is not less
than 5.degree. C. and less than 10.degree. C. (S1155), the
pre-applying time is set at 10 ms (S1156), and the process
continues to the S1180 where the prevoltage value V.sub.1 is
calculated.
[0214] In the case where the measured air temperature is not less
than 0.degree. C. and less than 5.degree. C. (S1160), the
pre-applying time is set at 20 ms (S1156), and the process
continues to the S1180 where the prevoltage value V.sub.1 is
calculated.
[0215] In the case where the measured air temperature is less than
0.degree. C. (S1160), the pre-applying time is set at 30 ms
(S1156), and the process continues to the S1180 where the
prevoltage value V.sub.1 is calculated.
[0216] The prevoltage value V.sub.1 calculated in the step S1180 is
given by for example an equation as follows:
Prevoltage value V.sub.1=(correction constant 1).times.(reference
temperature-measured temperature) Equation (1-1)
[0217] That is, the value obtained by multiplying (correction
constant 1) to the temperature difference against the reference
temperature, that is, 15.degree. C. will be the prevoltage value
V.sub.1. After the prevoltage value V.sub.1 is given, the process
continues to the step S1181 so that correction amount of the final
voltage reference value V.sub.0 is calculated and the final voltage
applying time is given. The final voltage reference value V.sub.0
is already given in the step S1125, but is also corrected using
correction expressed, for example, by the following equation.
Corrected final voltage value V.sub.0'=(final voltage reference
value V.sub.0)+(correction constant 2).times.(reference
temperature-measured temperature) Equation (1-2)
[0218] That is, the final voltage reference value V.sub.0 given in
the step S1125 is added to the value obtained by multiplying
(correction constant 2) to the temperature difference against the
reference temperature, that is, 15.degree. C., resulting in the
corrected final voltage value V.sub.0'.
[0219] Controlling as described so far is implemented so that the
applying voltage waveform is delicately altered as having been
shown in FIG. 25A corresponding with temperature, and consequently
the interface response waveform will approximately constant
regardless of temperatures as in FIG. 25C, and deformation is
completed at the time point t.sub.32. Under the circumstances, the
waiting time period of the timer 147' to be regarded as the
reference of completion of deformation is made T.sub.A slightly
longer than t.sub.32, and T.sub.A is stored in the memory of the
CPU 1130 in advance. In addition, in the step S1118 in FIG. 23 this
T.sub.A is treated as a judgment value of timer completion so that
execution of flow of and after the step S1131 is permitted after
the interface gets still.
[0220] On the other hand, in the case where in the step S151 the
measured temperature is not less than 15.degree. C., the waveform
of applying voltage B having been shown in FIG. 25B is selected
(S1170). In this relation, at the time of high temperature,
viscosity of the liquids 121 and 122 in the optical element 101
becomes low to result in occurrence of oscillating phenomena before
the interface completes deformation sometimes, and therefore by
applying voltage gradually increasing to reach a predetermined
final voltage reference value V.sub.0 at the startup after the
electric power supply is switched on, the interface oscillation
phenomena at the time of startup is planned to be suppressed.
[0221] In this waveform pattern, for a predetermined time period
before the final voltage reference value V.sub.0 to be applied to
the optical element 101 is applied (also hereinafter to be referred
to as pre-applying time), the voltage control is implemented so as
to gradually reach the final voltage reference value V.sub.0.
[0222] In the case where the measured air temperature is not less
than 15.degree. C. and less than 20.degree. C. (S1171), the
pre-applying time is set at 10 ms (S1172), and the process
continues to the S1181 where the corrected finally applying voltage
value V.sub.0. is calculated and time period of the finally
applying voltage is calculated.
[0223] In the case where the measured air temperature is not less
than 20.degree. C. and less than 30.degree. C. (S1173), the
pre-applying time is set at 20 ms (S1174), and the process
continues to the S1181 where the corrected finally applying voltage
value V.sub.0' is calculated and time period of the finally
applying voltage is calculated.
[0224] In the case where the measured air temperature is not less
than 30.degree. C. (S1173), the pre-applying time is set at 30 ms
(S1175), and the process continues to the S1181 where the corrected
finally applying voltage value V.sub.0' is calculated and time
period of the finally applying voltage is calculated.
[0225] Controlling as described so far is implemented so that the
applying voltage waveform is delicately altered as having been
shown in FIG. 25B corresponding with temperature, and consequently
the interface response waveform will approximately constant
regardless of temperatures as in FIG. 25D, and deformation is
completed at the time point t.sub.42. Under the circumstances, the
waiting time period of the timer 147' to be regarded as the
reference of completion of deformation is made T.sub.B slightly
longer than t.sub.42. and T.sub.B is stored in the memory of the
CPU 130 in advance. In addition, in the step S1118 in FIG. 23 this
T.sub.B is treated as a judgment value of timer completion so that
execution of flow of and after the step S1131 is permitted after
the interface gets still.
[0226] As described so far, the finally applying voltage value and
the waveform pattern of applying voltage corresponding to
temperatures are decided (S1182), and thus the state is returned to
the step 1127.
[0227] In addition, it is possible to implement optimum drive
control for respective temperatures by controlling the finally
applying voltage value and the waveform pattern of applying voltage
depending on temperature.
[0228] According to the above described fourth embodiment:
[0229] (1) The finally applying voltage value and the waveform
pattern of applying voltage to the optical element are controlled
corresponding with temperatures so that an optical apparatus that
can shorten the time period of deformation completion of the
optical element can be made available;
[0230] (2) Since the time period to drive the optical element could
be shortened actually, electric power consumption can be reduced;
and,
[0231] (3) Since exposure is prohibited until the deformation of
the optical element gets still, such an case that the photo-taking
operation of the optical apparatus is influenced is annulled, and
the like will be attained.
[0232] Incidentally, in this embodiment, the reference temperature
for switching the waveform pattern of the applying voltage is set
at 15.degree. C. and the pre-applying time is set for respective
temperatures, similar effects can be attained by setting the
reference temperature as well as the pre-applying time by
configuration of the optical element and the kinds and combination
of liquids thereof, etc.
[0233] In addition, the voltage was applied to the optical element
in two stages, but with a multi-stage arrangement involving more
stages similar effects can be attained.
[0234] Moreover, the corrected amount of the finally applying
voltage value as well as the pre-applying voltage value for
respective temperatures were given by calculation, but effects
similar to those in this embodiment can be attained as well by
storing, as having been shown in FIG. 26, for example, a table
decided by the temperature of the desired focal length and using it
as respective correction amounts.
[0235] Incidentally, in this embodiment, as an example of the
optical element, a digital still camera was taken, but it goes
without saying that also a video camera or a silver salt camera,
etc. other than that can be taken likewise without spoiling the
effects.
[0236] [Fifth Embodiment]
[0237] The above described fourth embodiment was an embodiment in
the case where voltages are applied to the optical element without
any thing being applied thereto. On the contrary hereto, the fifth
embodiment to be shown as follows is an configuration example in
which in the case where a voltage is applied to the optical element
and interface thereof is still an operation to alter its interface
shape was executed.
[0238] FIG. 27 and FIG. 30 are drawings related to the fifth
embodiment of the present invention.
[0239] FIG. 27 is the one in which a digital still camera as an
example of the optical element 101 as in the fourth embodiment was
applied to the optical apparatus. As for those similar to the ones
in the fourth embodiment, description thereon will be omitted.
[0240] In the above described drawing, the optical apparatus 150
has a W side zooming switch 201 for making respective optical
systems such as photo-taking optical system and observation optical
system such as a finder, etc. and the like zoom to the wide-angle
side and a T side zooming switch 202 for making the above described
optical systems zoom to the telephotographic side.
[0241] FIG. 28 and FIG. 29 are a control flow chart of the optical
apparatus 150 having been shown in FIG. 27. The control flow of the
optical apparatus 150 will be described with reference to FIG. 28
as well as FIG. 29 as follows.
[0242] Since the state from the step S1201 to the step S1203 up to
acceptance for setup of photographic conditions is similar to those
in the fourth embodiment, descriptions thereon will be omitted.
[0243] In the step S1204 distinction on whether or not the
photographer has operated the W side zoom switch 201 is
implemented. In the case no on-operation has been executed, the
process continues to the step S1205. Here, in the case where the W
side zoom switch 201 has been operated, the process continues to
the step S1221.
[0244] In the step S1205 distinction on whether or not the T side
zoom switch 202 has been operated by the photographer is
implemented. In the case no on-operation has been executed, the
process continues to the step S1206. Here, in the case where the T
side zoom switch 202 has been operated, the process continues to
the step S1221.
[0245] In the step S1206 distinction on, as in the fourth
embodiment, whether or not on-operation on the pre-photo-taking
switch (indicated as SW1 in the flow chart in FIG. 28) among the
operation switches 154 has been executed by the photographer is
implemented. In the case where the on-operation is not executed,
the state returns to the step S1203 so that acceptance for setup of
photographic conditions and distinguishing on operation of
respective zoom switches is repeated. Once the pre-photo-taking
switch is determined to have been operated on in the step S1206,
the process continues to the step S1211.
[0246] Since the control flow from the step S1211 to the step S1237
is similar to those in the fourth embodiment, descriptions thereon
will be omitted.
[0247] In the step S1221, to which the process continues in the
case where the W side zoom switch 201 or the T side zoom switch 202
was operated in the step S1204 or in the step S1205, distinction on
whether or not the timer 147' is in the midst of counting is
implemented. In the case where counting is not going on, the
process continues to the step S1222 and as in the fourth embodiment
a series of control flow from "detection of operated amount of zoom
switch" in the step S1222 to "timer start" in the step S1227 is
implemented, and therefore description thereon will be omitted.
[0248] On the other hand, in the case wherein the step S1221 it is
distinguished that the timer 147' is counting, that is, a
predetermined amount of voltage is applied to the optical element
101, the process continues to the subroutine of "finally applied
voltage correction" in the step S1228.
[0249] Next, correction on finally applied voltage will be
described with reference to FIG. 29 and FIG. 30.
[0250] In the step S1251, the counter value of the timer 147' is
reset. Next, in the step S1252, the operation quantity of the zoom
switch which has been operated is detected, and the corresponding
varied amount of focal length is calculated based on that operate
amount (S1253).
[0251] In the step S1254, which zoom switch has been operated is
distinguished. In the case where the W side zoom switch 201 has
been operated, the process continues to the step S1255, and in the
case where the T side zoom switch 202 has been operated, the
process continues to the step S1257.
[0252] The result that the W side zoom switch 201 has been operated
in the distinction in the step S1254 means that the voltage value
applied to optical element 101 is caused to increase to further
deform the interface 124 so that the focal length of the optical
element 101 is shortened, and therefore in the step S1255, the
direction in which finally applied voltage value is corrected as in
the direction indicated in FIG. 30A. In addition, from the voltage
value V.sub.A applied to the optical element 101, value V.sub.2
which is obtained by adding the correction value to the finally
applying voltage reference value V.sub.0 to be given by the varied
amount of focal length is decided as the corrected finally applied
voltage value in the case where the W side zooming switch 201 has
been operated, and therefore, V.sub.0 as well as its correction
amount is calculated in the step S1256.
[0253] Incidentally, the correction amount at this time may be
decided by calculation, or may be a table value in the memory in
the CPU 130 decided corresponding to the finally applied voltage
reference value V.sub.0. Thus, as shown in FIG. 30C, with V.sub.0
being the finally applied voltage value, the interface 124 of the
optical element 101 changes as shown in a broken line in accordance
with lapse of time, and deformation takes place only to an
optically unacceptable deformation amount, for example,
0.90.delta..sub.A with respect ot the desired deformation amount
.delta..sub.A at the final stage, but with V.sub.2 being the
finally applied voltage value, the interface 124 changes as shown
in a bold line in accordance with lapse of time, and deformation
reaches finally the desired amount .delta..sub.A. That is, the
desired focal length changes of the optical element 101 will have
been given.
[0254] On the other hand, the result that the T side zoom switch
202 has been operated in the distinction in the step S1254 means
that the voltage value applied to optical element 101 is caused to
decrease deformation amount of the interface 124 of the optical
element 101 so that the focal length of the optical element 101 is
lengthened, and therefore in the step S1257, the direction in which
finally applied voltage value is corrected as in the direction
indicated in FIG. 30B. In addition, from the voltage value VB
applied to the optical element 101, value V.sub.3 which is obtained
by adding the correction value to the finally applying voltage
reference value V.sub.0 to be given by the varied amount of focal
length is decided as the corrected finally applied voltage value in
the case where the T side zooming switch 201 has been operated, and
therefore, V.sub.0 as well as its correction amount is calculated
in the step S1258.
[0255] Incidentally, the correction amount at this time may be
decided by calculation, or may be a table value in the memory in
the CPU 130 decided corresponding to the finally applied voltage
reference value V.sub.0.
[0256] Thus, as shown in FIG. 30D, with V.sub.0 being the finally
applied voltage value, the interface 124 of the optical element 101
changes as shown in a broken line in accordance with lapse of time,
and deformation takes place only to an optically unacceptable
deformation amount, for example, 0.90.delta..sub.B with respect to
the desired deformation amount .delta..sub.B at the final stage,
but with V.sub.3 being the finally applied voltage value, the
interface 124 changes as shown in a bold line in accordance with
lapse of time, and deformation reaches finally the desired amount
.delta..sub.B.
[0257] That is, the desired focal length changes of the optical
element 101 will have been given.
[0258] When calculation of the finally applied voltage value as
well as its correction amount is completed in the step S1256 and in
the step S1258, the process continues to the "temperature
correction" subroutine in the step S1225.
[0259] At this time, with V.sub.2 or V.sub.3 being the finally
applied voltage value, the temperature correction toward the
finally applied voltage value described in the fourth embodiment is
implemented, but detailed description thereof will be omitted.
[0260] As having been described so far, when in the case where to
the optical element 101 is still in the midst of voltage
application an operation to alter its interface shape was executed,
since the correction amounts and the correction directions are
respectively set for the case in which alteration takes place from
the wide-angle side and for the case in which alteration takes
place from the telephotographic side even if the finally applied
voltage value directed to the desired focal length is V.sub.0, the
finally applied voltage value will differ. Thus, even in the case
where hysteresis has taken place in deformation of the interface
124 with respect to the voltage shift to be applied to the optical
element 101, setup of appropriate correction amount as well as the
correction direction can cancel its influence.
[0261] According to the above described fifth embodiment:
[0262] (1) Since the finally applied voltage value is respectively
decided according to applied voltage shifted direction to the
optical element, changes in optical characteristics of the optical
element become possible without being influenced by hysteresis;
and,
[0263] (2) since the optical element can be controlled canceling
influence of hysteresis, correct operation reflecting intention of
the photographer becomes possible, and the like will be
attained.
[0264] [Sixth Embodiment]
[0265] FIG. 31 and FIG. 32 are flow charts related to a sixth
embodiment of the present invention. Incidentally, the optical
apparatus of this embodiment shall be similar to the fifth
embodiment.
[0266] FIG. 31 and FIG. 32 are control flow charts on the optical
apparatus of this embodiment. The control flow on the optical
apparatus will be described with reference to FIG. 31 and FIG. 32
as follows.
[0267] As for the common control flow between FIG. 28 being the
control flow chart of the fifth embodiment and FIG. 31 being the
control flow chart of this embodiment, descriptions thereon will be
omitted. Here, the voltage application control method to the
optical element 101 after temperature correction was implemented in
the step S1325 (reference should be made to the following
description on "control of voltage to be applied" of the step
S1326) is different.
[0268] Under circumstances, in order to clear this issue, control
of voltage to be applied will be described with reference to FIG.
32 and FIG. 33.
[0269] In the step S1351 distinction on whether or not the zoom
switch operated by the photographer is the W side zoom switch 201
is implemented. In the case where the W side zoom switch 201 has
been operated, the process continues to the step S1352, and in the
case where the T side zoom switch 202 has been operated, the state
is goes forward to the step S1361.
[0270] In the step S1352, the first applying voltage value V.sub.4
for the corrected finally applied voltage value V.sub.0' given in
the step S1325 is calculated and its applying time t.sub.70 is set.
This first applying voltage value V.sub.4 is given by for example
the following equation:
First applying voltage value V.sub.4=(corrected finally applied
voltage value V.sub.0')-(constant) Equation (3-1)
[0271] "Constant" and application time in this equation (3-1) may
be those either read out from a memory stored in the CPU 130 or
given by an equation performed on the correction finally applied
voltage value V.sub.0'.
[0272] Thus, after the first applying voltage value V.sub.4 and its
applying time t.sub.70 are given, in the step S1353 applying the
first applying voltage value V.sub.4 is started, and concurrently
therewith the timer 147' starts counting (S1354). After counting
for the applying time set in the step S1352 is completed (S1355),
counting of the timer 147' is completed and application of
corrected finally applied voltage value V.sub.0' being the second
applying voltage starts (S1356 and S1357). And the state returns to
the step S1327.
[0273] In the step S1361, the third applying voltage value V.sub.5
for the corrected finally applied voltage value V.sub.0' given in
the step S1325 is calculated and its applying time t.sub.80 is set.
This third applying voltage value V.sub.5 is given by for example
the following equation:
Third applying voltage value V.sub.5=(corrected finally applied
voltage value V.sub.0') -(constant) Equation (3-2)
[0274] "Constant" and application time t.sub.80 in this equation
(3-2) may be those either read out from a memory stored inside the
CPU 130 or given by an equation performed on the correction finally
applied voltage value V.sub.0'.
[0275] Thus, after the third applying voltage value V.sub.5 and its
applying time t.sub.80 are given, in the step S1362 applying the
third applying voltage value V.sub.5 is started, and concurrently
therewith the timer 147' starts counting (S1363). After counting
for the applying time set in the step S1361 is completed (S1364),
counting of the timer 147 is completed and application of corrected
finally applied voltage value V.sub.0' being the fourth applying
voltage starts (S1365 and S1366). And the state returns to the step
S1327.
[0276] As having been described so far, regardless of the direction
of changes in focal length of the optical element 101, application
of voltage lower than the corrected finally applied voltage value
V.sub.0' for a predetermined time before the corrected finally
applied voltage value V.sub.0' is applied to the optical element
101 will make the direction to which the interface 124 of the
optical element 101 is made stable be the direction to which the
radius of curvature of the interface 124 is made small. That is,
even in the case where hysteresis has taken place in deformation of
the optical element 101, with voltage applying direction toward the
optical element 101 at the time when the interface 124 is made
stable being constant, consideration on only one direction of the
influence of hysteresis will become necessary and its correction
will become easy.
[0277] Incidentally, in the above described description, voltage
applying direction toward the optical element 101 at the time when
the interface is made stable should be the voltage value increasing
direction, but without being limited hereto, adoption of the
voltage value increasing direction can direct the influence of
hysteresis to a direction so that similar effects can be
attained.
[0278] Accordingly to the above described sixth embodiment, voltage
application is made in a constant direction when the interface of
the optical element is made stable so that it will become possible
to implement correction on the portion influenced by hysteresis of
the optical element easily.
[0279] [Seventh Embodiment]
[0280] The above described fourth embodiment and sixth embodiment
were modes of embodiment in the case where the optical element was
incorporated into the photo-taking optical system of the optical
apparatus. In contrast, the seventh embodiment described as follows
is an example of configuration in the case where the optical
element was incorporated into the optical system other than the
above described one.
[0281] FIG. 34 through FIG. 36 are drawings related to the seventh
embodiment of the present invention.
[0282] FIG. 34 is the one when the optical element 101 was
incorporated into the observatory optical system 330 of the optical
apparatus. As for those similar to the ones in the fourth
embodiment and the fifth embodiment, description thereon will be
omitted.
[0283] In the above described drawing, the optical apparatus 150
has an eyesight adjustment switch 159. This eyesight adjustment
switch 159 may be either a lever type one or push button type one,
and with operation thereof, the CPU 130 controls the power supply
means to alter the applying voltage to the optical element 101.
That is, operation of the eyesight adjustment switch 159 changes
focal length of the optical element 101 so that the focus of the
observed image can be matched with the diopter of the
photographer.
[0284] Reference numeral 330 denotes a observatory optical system
comprising a plurality of lens groups and are configured by first
lens group 331, second lens group 332, third lens group 333, vision
frame 334 disposed in the approximate focal position of this
optical system, and the optical element 101. Forward and backward
movement in the optical axis of the second lens group 332
implements zooming. In addition, the third lens group 333 is a
relay lens group without movements. Thereby, the observer can
observe the observatory image formed in the focal position through
the optical element 101.
[0285] FIG. 35 and FIG. 36 are control flow charts on the CPU 130
which the optical apparatus 150 having been shown in FIG. 34 has.
The control flow of the optical apparatus 150 will be described
with reference to FIG. 35 through FIG. 36 as follows.
[0286] In the step S1401, distinction on whether or not
on-operation of the main switch 152 is executed is implemented and
when the on-operation is not yet executed, a waiting mode state in
which operation of various switches is waited for remains. On the
other hand, in the step S1401, when on-switch operation of the main
switch 152 is distinguished, the waiting mode is overridden and the
process continues to the subsequent step S1402.
[0287] In the step S1402 the corrected finally applied voltage
value V.sub.0' of the optical element 101 stored in the CPU 130 is
confirmed. Incidentally, in the case where the optical apparatus
150 is used for the first time, the corrected finally applied
voltage value V.sub.0'=0V is set in the CPU 130.
[0288] In the step S1403, based on the result of the above
described step S1402, in the case where there is a set value in the
CPU 130, the process continues to the subroutine of "memory set"
while in the case where there is no memory value the process
continues to the step S1404. In the case where there is a set value
in the CPU 130, that set value is read out again (S1451), based on
that set value the corrected finally applied voltage value V.sub.0'
to the optical element 101 is set (S1452), and thereafter the power
supply means 144 is controlled to apply the voltage to the optical
element 101, and the state goes back to the original state
(S1453).
[0289] In the step S1404 setup of photographic conditions by a
photographer is accepted. For example, setup such as setup on
exposure control mode (shutter priority AE and program AE, etc.),
image quality mode (size in the number of recording pixels and size
of image compression rate, etc.), and the electronic flash mode
(compulsory flash and flash prohibition, etc.), etc. is
implemented.
[0290] In the step S1405 distinction on whether or not the eyesight
adjustment switch 159 has been operated by the photographer is
implemented. In the case no on-operation has been executed, the
process continues to the step S1406. Here, in the case where the
eyesight adjustment switch 159 has been operated, the process
continues to the step S1421.
[0291] In the step S1421, the operation quantity of the eyesight
adjustment switch 159 (operation direction and on-time period,
etc.) is detected, and the corresponding eyesight adjustment amount
is calculated based on that operate amount (S1422). As per that
calculation outcome, the finally applied voltage value V.sub.0 to
the optical element 101 is determined (S1423), "temperature
correction" described in the fourth embodiment is implemented
(S1424), and thereafter the output voltage of the power supply
means 131 is controlled so that the corrected finally applied
voltage value V.sub.0' is applied to the optical element 101
(S1425). And the state goes back to the step S1404. That is, in the
case where operation of the eyesight adjustment switch 159 goes on,
the step S1404 to the step S1425 are repeatedly executed so that
the process continues to the step S1406 at the time point when
on-operation of the eyesight adjustment switch 159 is over.
[0292] In the step S1406 distinction on whether or not on-operation
on the pre-photo-taking switch (indicated as SW1 in the flow chart
in FIG. 35) among the operation switches 154 has been executed by
the photographer is implemented. In the case where the on-operation
is not executed, the state returns to the step S1404 so that
acceptance for setup of photographic conditions and distinguishing
on operation of eyesight adjustment switch 159 is repeated. In
addition, once the pre-photo-taking switch is determined to have
been operated on in the step S1406, the process continues to the
step S1411.
[0293] Since the step S1411 to the step S1417 are similar to the
step S1111 to the step S1117 in the fourth embodiment, and the step
S1431 to the step S1435 are similar to the step S1132 to the step
S1136 in the fourth embodiment, descriptions thereon will be
omitted.
[0294] After the photographed image in the step S1435 is displayed
in the display 151, in the step S1436 distinction on whether or not
the off-operation of the main switch 152 is implemented. In the
case where the off-operation is not yet implemented on the main
switch 152, the process continues to the step 1404, and a series of
photo-taking operations from S1404 to S1435 are repeatedly
implemented.
[0295] In addition, in the case the off-operation was implemented
on the main switch 152 in the step S1436, the process continues to
the step S1437 to rewrite the corrected finally applied voltage
value V.sub.0' to the optical element 101 stored in the CPU 130 to
the corrected finally applied voltage value V.sub.0' immediately
prior to the off-operation of the main switch 152, and thereafter
the process continues to the step S1438 to stop voltage application
to the optical element 101 so that a series of photo-taking
operations come to an end.
[0296] As described so far, also when the optical element was
incorporated in the observatory optical system, it will become
possible to control the finally applied voltage value and the
waveform pattern of applying voltage to the optical element
corresponding with temperature. That is, the optical element may be
incorporated into any optical system so that similar effects can be
attained.
[0297] [Eighth Embodiment]
[0298] FIG. 37 through FIG. 40 are drawings related to the eighth
embodiment of the present invention. Since configurations in FIGS.
37, 38 and 39 are the same as those in FIGS. 16, 17 and 18,
descriptions will be omitted.
[0299] FIG. 40 is a control flow chart on the CPU 130 which the
optical apparatus 150 having been shown in FIG. 39 has. The control
flow of the optical apparatus 150 will be described with reference
to FIG. 39 and FIG. 40 as follows. Incidentally, as for the control
flow similar to that in the fourth embodiment, detailed
descriptions thereon will be omitted.
[0300] In the step S1501, distinction on whether or not
on-operation of the main switch 152 is executed by the photographer
is implemented and when the on-operation is not yet executed, the
state remains in the step S1501. In the step S1501, when on-switch
operation of the main switch 152 is distinguished, the CPU 130 gets
out of the sleep state so as to execute the step S1502 and
onward.
[0301] In the step S1502, as in the fourth embodiment, the ambient
temperature where the optical apparatus 150 is disposed, that is,
the periphery air temperature of the optical apparatus 150 is
measured with the temperature sensor 146.
[0302] In the step S1503 setup of photographic conditions by a
photographer is accepted.
[0303] In the step S1504 distinction on whether or not on-operation
on the pre-photo-taking switch (indicated as SW1 in the flow chart)
has been executed by the photographer is implemented. In the case
where the on-operation is not executed, the state returns to S1503
so that distinguishing on acceptance for setup of photographic
conditions is repeated.
[0304] Once the pre-photo-taking switch is determined to have been
operated on in the step S1504, the process continues to the step
S1511.
[0305] Since the step S1511 as well as the step S1512 are similar
to those in the fourth embodiment, description thereon will be
omitted.
[0306] In the step S1513 distinction on whether or not the received
light amount judged in the above described step S1512 is
appropriate is implemented. In addition, when in the present step
its appropriateness is recognized, the process continues to the
step S1514.
[0307] On the other hand, when in the step S1513 it is
distinguished that the received light amount judged in the above
described step S1512 is not appropriate, the state leaps to the
step S1521. Since the step S1521 as well as the step S1522 are
similar to those in the fourth embodiment, description thereon will
be omitted. In the step S1523 the actual received light amount is
compared with the appropriate received light amount so as to
calculate the appropriate transmittance of the optical element 801
in the photo-taking optical system 430. In the step S1524 the
control voltage (finally applied voltage value V.sub.0) is
calculated in order to acquire the appropriate transmittance
calculated in the above described step S1523. In particular, the
ROM of the CPU 130 stores the relationship on the transmittance
toward the applied voltage as the form of look-up table, the
finally applied voltage value V.sub.0 with respect to the
transmittance calculated in the step S1523 is acquired with
reference to the table.
[0308] In the step S1525 temperature correction with respect to the
finally applied voltage value V.sub.0 is implemented as in the
fourth embodiment while in the step S1526 the power supply means
131 are controlled with the finally applying voltage reference
value and applying waveform pattern to be applied to the optical
element 801 decided in the subroutine of the above described
"temperature correction" so that a voltage is applied to the
optical element 801. Concurrently therewith, counting of the timer
147 is started (S1527). After the step S1527 is executed, the state
goes back to the step S1511, and the steps from acquisition of the
image signals of the step S1511 to the step S1527 are repeated
until the incident light amount into the photo-taking means 144
becomes appropriate. And when the incident light amount into the
photo-taking means 144 become appropriate, the process continues
from the step S1513 to the step S1514.
[0309] Since the step S1514 to the step S1537 are similar to those
in the fourth and the fifth embodiments, description thereon will
be omitted.
[0310] [Ninth Embodiment]
[0311] FIG. 41 shows another control flow chart when the above
described optical element 101 (shown in FIG. 2) was applied to the
optical apparatus 150 (in FIG. 9). Since this flow has the step
2123 deciding the applying voltage although the step 123 decides
the duty ratio in FIG. 10, representing only difference,
descriptions on other points will be omitted.
[0312] [Tenth Embodiment]
[0313] The above described ninth embodiment was a mode of
embodiment in which immediately after completion of photo-taking
operation power supply to the optical element is switched off.
Here, the case where the photographer can set the time for putting
off power supply to the optical element will be described as the
tenth embodiment of the present invention as follows with reference
to FIG. 42 to FIG. 44.
[0314] FIG. 42 is the one in which the optical element 101 was
applied to an optical apparatus equivalent to a digital still
camera as in the ninth embodiment. As for those similar to the ones
in the above described ninth embodiment, description thereon will
be omitted.
[0315] In FIG. 42, the CPU 142 has a timer 146 in its interior. The
timer 146 is for counting set time as described later. The optical
apparatus 141 has a menu switch 158. This menu switch 158 is to
implement respective settings such as brightness adjustment of the
display 151 and setting on photo-taking date and time, etc. and has
among those setting items an item to set the time for power supply
to the optical element 101 after completion of photography. In
addition, as for those setting items, at least two kinds of
setting, for example, the setting to put off power supply
immediately after completion of photography and the setting to put
off power supply in ten seconds after completion of photography
shall be feasible.
[0316] FIG. 43 and FIG. 44 are control flow charts on the CPU 142
which the optical apparatus 141 having been shown in FIG. 42 has,
which will be described with reference to FIG. 42 to FIG. 44 as
follows.
[0317] At first, in the step S2201, distinction on whether or not
on-operation of the main switch 152 is executed is implemented and
when the on-operation is not yet executed, the state enters a
waiting mode state in which operation of various switches is waited
for. Thereafter, when on-switch operation of the main switch 152 is
distinguished, the waiting mode is overridden and the process
continues to the step S2202. In addition, in this step S2202 set
values of the timer 146 stored in the CPU 142 is confirmed.
Incidentally, in the case where the optical apparatus 141 is used
for the first time, a certain set value (for example counted
value=0) is stored in the CPU 142.
[0318] In the next step S2203 setup of photographic conditions by a
photographer is accepted. For example, setup such as setup on
exposure control mode (shutter priority AE and program AE, etc.),
image quality mode (size in the number of recording pixels and size
of image compression rate, etc.), and the electronic flash mode
(compulsory flash and flash prohibition, etc.), etc. is
implemented. In addition, in the next step S2204 it is judged
whether or not the menu switch 158 has been operated by the
photographer, and in the case no on-operation has been executed,
the process continues to the step S2205. In addition in the case
where the menu switch 158 has been operated, the process continues
to the subroutine of the step S2210. This sub-routine will be
described with reference to FIG. 44 as follows.
[0319] In the step S2251 in FIG. 44 it is judged to which the count
value of the timer 146 is set by the menu switch 158, and in the
next step S2252 that setup value is replaced with the setup value
stored in the CPU 142, and thereafter the process continues to the
step S2205 in FIG. 43.
[0320] Incidentally, operation of the menu switch 158 implements
brightness adjustment of the display 151 and setting on
photo-taking date and time, etc., but since the flow is similar to
the above described one, description thereon will be omitted
here.
[0321] Back to FIG. 43, in the step S2205 it is judged whether or
not the zoom switch 153 was operated by the photographer, and in
the case no on-operation has been implemented, the process
continues to the step S2206. In addition, in the case where the
zoom switch 153 is operated, the process continues to the step
S2221.
[0322] Since operations from the step S2221 to the step S2224 are
similar to the above described ones, descriptions thereon will be
omitted.
[0323] In the next step S2224, a voltage is applied to the optical
element 101, and thereafter, in the next step S2225, in the case
where the timer 146 has started counting, that count value is
reset, and in the subsequent step S2226 the timer 146 is made to
start counting again so that the state goes back to the step
S2203.
[0324] That is, in the case where operation of the zoom switch 153
goes on, the step S2205 to the step S2226 are repeatedly executed
so that the process continues to the step S2206 at the time point
when on-operation of the zoom switch 153 is over. That is, while
the zoom operation is going on, the timer is not practically caused
to start counting.
[0325] In the step S2206 it is judged whether or not on-operation
on the pre-photo-taking switch among the operation switches 154 has
been executed by the photographer. In the case no on-operation has
been executed, the process continues to the step S2207 and when the
timer 146 has started counting it is judged here whether or not the
value counting is completed, or the state returns to the Step S2203
in the case where the counting is not completed so that acceptance
for setup of photographic conditions and judgment on operation of
the menu switch 158 and the zoom switch 153 are repeated. On the
other hand, in the case where value counting of the timer 146 is
completed in the step S2207, the process continues to the step
S2208, and after the counted value of the timer 146 is reset, the
process continues to the step S2237 (the flow thereafter will be
described later).
[0326] In addition, in the case where in the above described step
S2206 it is judged that on-operation on the pre-photo-taking switch
has been executed, the process continues to the step S2211.
[0327] In the case where the on-operation of the photo-taking
switch is executed in the step S2217, since the step S2211 to the
step S2234 are similar to those in the above described ninth
embodiment, descriptions thereon will be omitted.
[0328] When the process continues to the next step S2235, the
photographed image is displayed in the display 151 here, and in the
next step S2236 it is judged whether or not the counting value of
the timer 146 is set. In the case where the counting value of the
timer 146 is not set, the process continues to the step S2237 to
control the power supply means 144 and to switch off the voltage
application to the optical element 101 so that a series of
photo-taking operation comes to an end.
[0329] In addition, in the case where in the above described step
S2236 a counting value of the timer 146 is set, the state returns
to the step S2203 again.
[0330] Hereafter, in the case where various kinds of switches are
not operated during counting, until that counting value is
completed, each step of step sequence of S2203 to S2204 to S2205 to
S2206 to S2207 to S2203 is repeated, but when the counting is
completed, the process continues from the step S2207 to the step
S2208, the counting value of the above described timer 146 is
reset, and the process continues to the step S2237 to switch off
the voltage application to the optical element 101 so that a series
of photo-taking operation comes to an end. Incidentally, when
on-operation on the photo-taking switch is not executed in the
above described step S2217, the process continues to the step
S2207. Since configuration is made like this, voltage application
to the optical element 101 is suspended automatically when
photography is not implemented for a set time after zoom operation
is executed. In addition, when photo-taking operation is executed
within the set time, and photography is completed, but the set time
has not yet lapsed, suspension of voltage application is executed
after the set time has lapsed thereafter.
[0331] According to the above described tenth embodiment, effects
as described below will be attained:
[0332] 1) Regardless of the photo-taking operation, in the case
where operation on various operation switch group is not executed,
the voltage application to the optical element 101 can be switched
off, and therefore power saving of the optical apparatus in its
entirety will become feasible.
[0333] 2) Since the photographer himself/herself can set the
voltage applying time to the optical element 101, power saving
operation reflecting the photo-taking situation and the
photographer's intention, etc. will become possible.
[0334] [Eleventh Embodiment]
[0335] The tenth embodiment was a mode of embodiment in the case
where the optical element was applied to focal length alterations
of various optical systems of the optical apparatus. Here, the case
of application as an optical filter previously applied by the
present applicant will be described as the eleventh embodiment of
the embodiments in the present invention with reference to FIGS.
45A to 45C through FIG. 48.
[0336] FIGS. 45A to 45C are sectional views to describe
configuration of the optical element 201 related to the eleventh
embodiment of the present invention and drawings to describe
operations in the case of using it as an optical filter. The
optical element is configured similar to the one shown in the above
described FIG. 2, that is, reference numeral 202 corresponds with
the transparent substrate 102, reference numeral 203 does with
transparent electrode (ITO) 103, reference numeral 204 does with
the insulating layer 104, reference numeral 205 does with the
container 105, reference numeral 206 does with the cover plate 106,
reference numeral 207 does with the diaphragm plate 107, reference
numeral 211 does with the water-repelling film 111, reference
numeral 212 does with the hydrophilic film 112, reference numeral
213 does with the hydrophilic film 113, reference numeral 223 does
with the optical axis 123, reference numeral 225 does with the
stick-like electrode 125, and reference numeral 226 does with the
power supply means 126 respectively.
[0337] The points and the configuration of the optical element 201
that are difference from the optical element 101 are as
follows.
[0338] The liquid chamber of the optical element 201 will be filled
with two kinds of liquids as described below. At first, onto the
water-repelling film 211 on the insulating layer 204 a
predetermined quantity of a second liquid 222 is dripped. The
second liquid 222 is colorless and transparent, and silicone oil
which has specific gravity of 0.85 and a refractive index of 1.38
in a room temperature will be used. On the other hand, the
remaining space inside the liquid chamber is filled with the first
liquid 221. This first liquid 221 is electrolytic solution, which
is a mixture of water and ethyl-alcohol at a predetermined ratio
and moreover to which a predetermined quantity of sodium chloride
is added, with specific gravity 0.85 and with refractive index 1.38
under a room temperature. Moreover, to he first liquid 221,
uncolored water-soluble dye, for example, carbon black or materials
in the titan oxide system are added. That is, for the first and the
second liquid, liquids which have the same specific gravity and
refractive index but have different light beam absorptive powers
and are insoluble each other are selected. There, the both liquids
form an interface 224 and each of them exists independently without
being mixed together.
[0339] Next, the shape of the above described interface will be
described.
[0340] At first, in the case where no voltage is applied to the
first liquid, the shape of the interface 224 is determined by
interfacial tension between the both liquids, interfacial tension
between the first liquid and the water-repelling film 211 or the
hydrophilic film 212 on the insulating layer 204, interfacial
tension between the second liquid and the water-repelling film 211
or the hydrophilic film 212 on the insulating layer 204, and volume
of the second liquid. In this mode of embodiment selection of
materials is implemented so that interfacial tension between
silicone oil being material for the second liquid 222 and the
water-repelling film 211 becomes relatively small. That is,
wet-aptness is high between the both materials and therefore the
outer periphery of lens-shaped drops which the second liquid 222
form tends to expand and is stabilized where the outer periphery
corresponds with the application region of the water-repelling film
211. That is, the diameter A1 of the bottom surface of the lens
which the second liquid 222 forms is equal to the diameter D1 of
the water-repelling film 111. On the other hand, since the specific
gravity of the both liquids is the same as described above, gravity
are not influential. Then the interface 224 becomes spherical, and
the radius of curvature as well as the height hi thereof are
determined by the volume of the second liquid 222. In addition,
thickness of the first liquid on the optical axis will be t1.
[0341] Here, the second liquid 222 is practically transparent, but
the first liquid 221 has a predetermined light beam absorptive
power due to an added light absorbing material. There, when a light
flux is emitted in from the opening of the diaphragm plate 207, the
light beam equivalent to the light length of the first liquid 221
is absorbed and the intensity of the light flux emitted out from
the transparent substrate 202 decreases. That is, since reducing
rate in the light intensity is in proportion to thickness on the
optical axis of the first liquid 221 (t1 in FIG. 11), deformation
of the interface 224 by the voltage control of the power supply
means 226 can realize an optical element which can freely change
the transmitting light amount. In addition, the refractive indexes
for the first and the second liquids are made to be the same and
only intensity of the emitted light can be changed without changing
the direction of the incident light flux.
[0342] FIGS. 45A to 45C are drawings to describe, in further
detail, operations in the case where the optical element 201 is
used as a variable ND filter.
[0343] FIG. 45A shows the case where the output voltage of the
power supply means 226 brought into connection with the optical
element 201 is zero or extremely low V1.
[0344] As for the shape of the interface 224 at this time, the
bottom surface of the lens forming the second liquid 222 has a
diameter being A1 and a height being h1. In addition, thickness on
the optical axis of the first liquid 221 is t1. L.sub.IN is a light
flux irradiated from above the optical element 201 and emitted into
the opening of the diaphragm 207, and L.sub.OUT is a light flux
emitted from the optical element 201. In addition, the ratio
L.sub.OUT against the light flux L.sub.IN will be the transmittance
of the optical element 201, but since the thickness t1 on the
optical axis of the first liquid 221 is large, the transmittance
will become low. In addition, as for the light amount distribution
of the emitted light flux L.sub.OUT, larger the distance from the
optical axis, that is, the incident height is, the light amount
will be decreased, but since the opening diameter D3 of the
diaphragm 207 is made small against the diameter A1 of the bottom
surface of the lens which the liquid 222 forms, the light amount
distribution of the emitted light flux L.sub.OUT can be regarded as
approximately unanimous.
[0345] FIG. 45B shows the case of the output voltage of the power
supply means 226 being V2 larger than V1.
[0346] At this time, the diameter of the bottom surface of the lens
which the second liquid 222 forms is A2, and the height thereof is
h2. In addition, thickness of the first liquid 221 on the optical
axis is t2 smaller than t1 in FIG. 45A. There, the transmittance of
the light flux will become larger than in the case of FIG. 45A.
[0347] FIG. 45C shows the case of the output voltage of the power
supply means 226 being V3 further larger than V2.
[0348] At this time, the diameter of the bottom surface of the lens
which the second liquid 222 forms will shrink to A3, and the top of
the interface 224 will brought into contact with the hydrophilic
film 213 formed on the lower surface of the cover plate 206 to
become flat. In addition, the diameter of this flat portion is
equal to the diameter D3 of the opening of the diaphragm 207 or
larger than D3. Consequently, the thickness on the optical axis of
the first liquid 221 becomes zero, as the transmittance will become
further larger than in the case of FIG. 45B. Thereafter, even if
the output voltage of the power supply means 226 is made to
increase further, the interface 224 inside the opening of the
diaphragm 207 is not deformed, and therefore, the transmittance in
the case where the optical element was used as a variable ND filter
will remain constant. The transmittance at this time is expressed
by multiplication of transmittances of the transparent substrate
202, the transparent electrode 203, the insulating layer 204,
water-repelling film 211, the second liquid 222, the hydrophilic
film 213, and the cover plate 206.
[0349] Incidentally, when the applying voltage of the power supply
means 226 is returned from the state in FIG. 45C to V1, the
interface tension of the both liquids will go back to the original
state. At this time, wet-aptness is good between the first liquid
221 and the hydrophilic film 213 while wet-aptness is poor between
the second liquid 222 and the hydrophilic film 213, and therefore
the second liquid 222 leaves the hydrophilic film 213 to come back
to the state in FIG. 45A. That is, deformation of the interface 224
of the present optical element is reversible on changes in the
applying voltage.
[0350] FIG. 46 is a graph showing relationship on the light
transmittance of the optical element 201 for the voltage to be
applied to the optical element 201, and as the applying voltage
increases, the transmittance rises up and at the level where the
applying voltage reaches V.sub.3, the transmittance gets
saturate.
[0351] FIG. 47 is the one in which the optical element 201 was
applied to an optical apparatus. In this embodiment, the optical
apparatus 141 will be exemplified, for description, by so-called
digital still camera which converts a still image into electric
signals with photo-taking means and records them as digital
data.
[0352] Reference numeral 430 denotes a photo-taking optical system
comprising a plurality of lens groups and are configured by first
lens group 431, second lens group 432, and the third lens group 433
so that forward and backward movement in the direction of optical
axis of the above described first lens group 431 implements focus
adjustment while forward and backward movement in the direction of
optical axis of the above described second lens group 432
implements zooming. The above described third lens group 433 is a
relay lens group without movements. In addition, the optical
element 201 is disposed between the second lens group 432 and the
third lens group 433. The photo-taking means 134 is disposed in the
focal position (planned image forming surface) of the photo-taking
optical system 430.
[0353] Next, operation of the optical element 201 in this eleventh
embodiment will be described.
[0354] Dynamic range of luminance of subjects existing in the
natural world is extremely large, and in order to limit this within
a predetermined range, normally the interior of the photo-taking
optical system has a mechanical diaphragm mechanism to adjust light
amount of the photo-taking light flux. However, it is difficult to
make the mechanical diaphragm mechanism small, and under a state of
small diaphragm that the diaphragm opening is small, by diffraction
phenomena of the light beam due to end surface of diaphragm wings,
the resolution of the subject image decreases.
[0355] Thus, in this eleventh embodiment, the optical element 201
is used as a variable ND filter replacing the above described
mechanical diaphragm mechanism so that without giving rise to the
above described defects, the light amount passing through the
photo-taking optical system is adjusted appropriately.
[0356] FIG. 48 is a control flow chart on the CPU 142 which the
optical apparatus 141 having been shown in FIG. 47 has, and the
chart will be described with reference to FIG. 47 and FIG. 48.
Incidentally, as for the control portions similar to those in the
above described FIG. 43, detailed description thereof will be
omitted.
[0357] At first, in the step S2401, distinction on whether or not
on-operation of the main switch 152 is executed by the photographer
is implemented and when the on-operation is not yet executed, the
state remains in the step S2401. On the other hand, when on-switch
operation of the main switch 152 is distinguished, the CPU 142 gets
out of the sleep state so as to execute the step S2402 and
onward.
[0358] In the step S2402 the set values of the timer 146 stored in
the CPU 142 is confirmed. In addition, in the next step S2403 setup
of photographic conditions by a photographer is accepted, and in
the subsequent step S2404 it is judged whether or not on-operation
of the menu switch 158 has been executed by the photographer, and
in the case no on-operation has been executed, the process
continues to the step S2405. Here, in the case where the menu
switch 158 has been operated, the process continues to the subflow
of the step S2410 (similar to the step S2210).
[0359] When the process continues to the step S2405, judgment as to
whether or not on-operation on the pre-photo-taking switch has been
executed by the photographer, and in the case no on-operation has
been executed, the process continues to the step S2406, and when
the timer 146 has started counting it is judged whether or not the
value counting is completed, or the state returns to the Step S2403
in the case where the counting is not completed so that acceptance
for setup of photographic conditions and judgment on operation of
the menu switch 158 are repeated. On the other hand, in the case
where value counting of the timer 146 is completed in the step
S2206, the process continues to the step S2407, the set value of
the timer 146 is reset, and thereafter the process continues to the
step S2437.
[0360] In addition, in the case where in the above described step
S2405 is judged that on-operation on the pre-photo-taking switch
has been executed, the process continues to the step S2411.
[0361] Since the step S2411 and step S2412 are similar to the
control in the above described FIG. 43, descriptions thereon will
be omitted.
[0362] The process continues to the next step S2413 to judge here
whether or not the received light amount judged in the above
described step S2412 is appropriate. In addition, when in the
present step its appropriateness is recognized, the process
continues to the step S314.
[0363] On the other hand, when in the step S2413 it is judged that
the received light amount judged in the above described step S2412
is not appropriate, the state leaps to the step S2421, in which the
actual received light amount is compared with the appropriate
received light amount so as to calculate the appropriate
transmittance of the optical element 201 inside the photo-taking
optical system 430. In addition, in the next step S2422 the control
voltage is calculated in order to acquire the appropriate
transmittance calculated in the above described step S2421. In
particular, since the ROM of the CPU 142 stores the relationship on
the transmittance toward the applied voltage shown in FIG. 46 as
the form of look-up table, the applied voltage toward the
transmittance calculated in the step S421 is acquired with
reference to the table.
[0364] In the next step S2423 the output voltage of the power
supply means 144 is controlled so that the voltage acquired in the
above described step S2422 is applied to the optical element 201.
Thereafter, the state returns to the step S2411, and until the
incident light amount into the photo-taking means 134 becomes
appropriate, the steps from preview image acquisition to the
control on the power supply means 144 are executed repeatedly. In
addition, when the incident light amount into the photo-taking
means 134 becomes appropriate, the state shifts from the step S2413
to the step S2414.
[0365] Since the step S2414 to the step S2434 are similar to the
control in the above described FIG. 43, descriptions thereon will
be omitted.
[0366] In the next step S2435, the photographed image is displayed
in the display 151, and thereafter the process continues to the
step S2436, in which it is judged whether or not the counting value
of the timer 146 is set. In the case where the counting value of
the timer 146 is not set, the process continues to the step S2437
to control the power supply means 144 and to switch off the voltage
application to the optical element 101 so that a series of
photo-taking operation comes to an end.
[0367] In addition, in the case in the step S2436 a counting value
of the timer 146 is set, the state returns to the step S2403
again.
[0368] Hereafter, in the case where various kinds of switches are
not operated during counting, until that counting value is
completed, each step of step sequence of S2403 to S2404 to S2405 to
S2406 to S2403 is repeated, but when the counting is completed, the
process continues from the step S2406 to the step S2407, the
counting value of the timer 146 is reset here, and then the process
continues to the state S2437 to switch off the voltage application
to the optical element 201 so that a series of photo-taking
operation comes to an end.
[0369] According to the above described eleventh embodiment,
effects as described below will be attained:
[0370] 1) Regardless of the photo-taking operation, in the case
where operation on various operation switch group is not executed,
the voltage application to the optical element 201 can be switched
off, and therefore power saving of the optical apparatus in its
entirety will become feasible.
[0371] 2) Since the photographer himself/herself can set the
voltage applying time to the optical element 201, power saving
operation reflecting the photo-taking situation and the
photographer's intention, etc. will become possible. That is,
regardless of the mode of use of the optical element, similar
effects can be made attainable.
[0372] [Twelfth Embodiment]
[0373] (This embodiment is the one which detects on capacitance of
the optical element 101 and utilizes its detection outcome to
control the optical apparatus and detect failures.)
[0374] Prior to describing the twelfth embodiment, additional
descriptions on the optical element shown in FIG. 2 will be made.
In the configuration shown in the above described FIG. 2, the
optical element 101 has a capacitor structure with the first liquid
121 being one electrode and with the transparent electrode 103
being the other electrode. Here, since thicknesses of the
water-repelling film 111 and the hydrophilic film 112 are extremely
thin, these existence is ignored, and if area of the portion where
the first liquid 121 and the insulating layer 104 are brought into
contact is assumed as S1 and thickness of the insulating layer 104
is also assumed as d, the optical element 101 is a capacitor with
electrode plate area of S1 and the inter-electrode gap d, and as
the interface shape 124 is deformed to give rise to changes in the
area S1, the capacitor's capacitance alters.
[0375] Here, when the switch 127 (in FIG. 2) is operated to close
so that a voltage is applied to the first liquid 121, electric
capillary phenomenon causes the interfacial tension between the
first liquid 121 and the hydrophilic film 112 to decrease and the
first liquid trespasses the interface between the hydrophilic film
112 and the water-repelling film 111 to penetrate into the
water-repelling film 111. Consequently, as in FIG. 3, the diameter
of the bottom surface of the lens which the second liquid forms
decreases from A1 to A2 while its height increases from h1 to h2
and the area increases from S1 to S2. In addition, thickness of the
first liquid on the optical axis will be t2. Thus, application of
voltage to the first liquid 121 changes balance in the interfacial
tensions of the two kinds of liquid so that the interface between
the two liquids is deformed.
[0376] In addition, the first as well as the second liquid have
different refractive indexes to provide with a power as an optical
lens and therefore the optical element 101 will be a variable focul
lens with deformation of the interface 124.
[0377] As a result thereof, as in FIG. 3, the optical element 101
is equivalent to a capacitor in terms of energy, and its
capacitance is proportional to the area where the first liquid 121
and the insulating layer 104 are in contact. Accordingly, the
optical element 101 of the present invention, in which deformation
of the interface 124 gives rise to change in capacitance, has a
characteristic that higher the applying voltage is, larger the
capacitance becomes.
[0378] Next, with reference to FIG. 49 and FIGS. 51A to 51E, the
configuration and a producing method of the power supply means used
in this embodiment will be described.
[0379] Reference numeral 130 denotes a central processing unit
(hereinafter to be abbreviated to CPU) to control operation of a
later-described optical apparatus 150 in its entirety, and is
one-chip microcomputer having ROM, RAM, EEPROM, A/D converter
function, D/A converter function, and PWM function. Reference
numeral 131 denotes power supply means for applying voltages to the
optical element 101, and its configuration will be described as
follows.
[0380] Reference numeral 132 denotes a direct current electric
power supply incorporated into the optical apparatus 150 such as a
dry cell, etc., reference numeral 133 denotes a DC/DC converter to
increase the voltage outputted from the electric power supply 132
to a desired voltage value corresponding with control signal of the
CPU 130, reference numerals 134 and 135 are amplifiers to amplify
in accordance with controlling signals of the CPU 130, for example,
frequency/duty ratio variable signals to be realized by PWM
function the signal levels to reach voltage levels increased with
the DC/DC converter 133. In addition, the amplifier 134 is brought
into connection with the transparent electrode 103 being the second
electrode of the optical element 101 and the amplifier 135 with a
stick-like electrode 125 being the first electrode of the optical
element 101 respectively via LC upstanding resonance circuit 162 of
the capacitance detection means 161 to be described later.
[0381] That is, corresponding with the controlling signals of the
CPU 130, output voltage of the electric power supply 132 will be
applied to the optical element 101 by the DC/DC converter 133, the
amplifier 134 and the amplifier 135 with a desired voltage value,
frequency and duty.
[0382] FIGS. 51A to 51E are explanatory views describing voltage
waveforms to be outputted from the amplifiers 134 and 135.
Incidentally, under assumption that a voltage of 100V was outputted
into the amplifiers 134 and 135 from the DC/DC converter 133
respectively, following description will be implemented.
[0383] As having been shown in FIG. 51A, the amplifiers 134 and 135
are respectively brought into connection with the optical elements
101. From the amplifier 134, as shown in FIG. 51B, a voltage of
rectangular waveform with desired frequency and duty ratio is
outputted by the controlling signals of the CPU 130. On the other
hand, from the amplifier 135, as having been shown in FIG. 51C, a
voltage of rectangular waveform with the opposite phase of the
amplifier 134, the same frequency and the same duty ratio is
outputted by the controlling signals of the CPU 130. This will
cause the voltage to be applied between the transparent electrode
103 and the sticklike electrode 125 of the optical element 101 to
become a rectangular waveform of .+-.100V, that is, an alternate
voltage as shown in FIG. 51D.
[0384] Therefore, an alternate voltage will be applied to the
optical element 101 with the power supply means 131.
[0385] Incidentally, since an effective voltage applied to the
optical element 101 from the application start can be expressed as
in FIG. 51E, hereafter the waveform of the alternate voltage
applied to the optical element 101 shall be expressed according to
the FIG. 51E.
[0386] Incidentally, in the above described description, a
rectangular waveform voltage was described to be outputted from the
amplifiers 134 and 135, but it goes without saying that likewise
configuration will be taken for sine waves.
[0387] In addition, in the above described description, the case
where the electric power supply 132 is incorporated into the
optical apparatus 150 was described, but the case where an exterior
type electric power supply or power supply means implement
alternate application into the optical element 101 will do as
well.
[0388] Next, with reference to FIG. 49, configuration of the
capacitance detection means and the detection method of this
embodiment will be described. Applying an alternate current drive
voltage E.sub.0 with a predetermined frequency f.sub.0 to the
stick-like electrode 125 being the first electrode of the optical
element 101 having an unknown capacitance from the power supply
means 131 having output impedance Z.sub.0, the electric current
i.sub.0 that flew out from the transparent electrode 103 being the
second electrode of the optical element 101 will flow into the
series LC resonance circuit 162 having impedance Zs, giving rise to
detection voltage Es in the middle point of the series LC resonance
circuit 162. This detected voltage Es will be proportionate to the
electric current i.sub.0.
[0389] In addition, the detection voltage Es in the middle point of
the series LC resonance circuit 162 is amplified by A times with
the amplifier 163 so that the detection voltage A of the amplifier
163.times.Es is converted into direct voltage with the AC/DC
conversion means 164 to be supplied to CPU 130.
[0390] In addition, here the resonance circuit in series was used
as means to detect capacitance, but a bridge in parallel used in an
LCR meter known as an capacitance detection apparatus and the like
may be used.
[0391] FIG. 50 is a graph expressing relationship between the drive
voltage E.sub.0 and the detected voltage Es generated in the middle
point of the series LC resonance circuit 162. Capacitance falls
within the range of C1<C2. In addition, (d) C=0 in FIG. 50 is a
graph showing relationship between the drive voltage and the
detected voltage when the circuit was short-circuited in FIG.
49.
[0392] The optical element 101 is an element having a capacitor
structure, and its capacitance is variable with respect to the
applying voltage, and higher the applying voltage is, larger the
capacitance becomes.
[0393] When the drive voltage E.sub.01 is applied by the power
supply means 131, the interface shape 124 of the optical element
101 is deformed and its capacitance will become C1, giving rise to
the detected voltage Es1.
[0394] Next, since application of Eo2 larger than the drive voltage
of Eo1 will further deform the interface shape 124 of the optical
element 101, the capacitance of the optical element 101 will become
C2, giving rise to the detected voltage Es2.
[0395] Therefore, the relationship between the drive voltage
E.sub.0 on the optical element 101 and the detected voltage Es will
represent a curve as (a) in FIG. 50.
[0396] FIG. 52 is the one in which the optical element 101 was
applied to an optical apparatus having approximately the same
configuration as in FIG. 9, and detailed descriptions thereon will
be omitted.
[0397] Reference numeral 146 in the drawing denotes a look-up table
provided within the CPU 130, which is a corresponding table on the
focal length f of the photo-taking optical system 140, the drive
voltages Eo of the power supply means 131, and the detected voltage
Es of the electrostatic detecting means, and by reading them out
the voltage to be applied to the optical element 101 is controlled.
In addition, reference numeral 161 denotes a capacitance detection
means having been shown in FIG. 49.
[0398] FIG. 53 and FIG. 54 are control flow charts on the CPU 130
which the optical apparatus 150 having been shown in FIG. 52 has.
The control flow of the optical apparatus 150 will be described as
follows.
[0399] In the step S3101, distinction on whether or not
on-operation of the main switch 152 is executed is implemented and
when the on-operation is not yet executed, a waiting mode state in
which operation of various switches is waited for remains. In the
step S3101, when on-switch operation of the main switch 152 is
distinguished, the waiting mode will be overridden and the process
continues to the subsequent step S3102 and onward.
[0400] In the step S3102 setup of photographic conditions by a
photographer is accepted. For example, setup such as setup on
exposure control mode (shutter priority AE and program AE, etc.),
image quality mode (size in the number of recording pixels and size
of image compression rate, etc.), and the electronic flash mode
(compulsory flash and flash prohibition, etc.), etc. is
implemented.
[0401] In the step S3103 distinction on whether or not the zoom
switch 153 has been operated by the photographer is implemented. In
the case no on-operation has been executed, the process continues
to the step S3104. Here, in the case where the zoom switch 153 has
been operated, the process continues to the step S3121. In the step
S3121, the operation quantity of the zoom switch 153 (operation
direction and on-time period, etc.) is detected, altered designated
value with respect to the focal length of the photo-taking optical
system 140 is calculated based on that operation quantity, and the
focal length f after the change is calculated (3122). After the
calculations are completed, the process continues to the subroutine
of "applying voltage control" of the next step S3123.
[0402] In the step S3141 the drive voltage E.sub.0 is calculated in
order to acquire the focal length f calculated in the above
described step S3122. In particular, since the ROM in the CPU 130
stores the relationship between the drive voltage E.sub.0 and the
detected voltage E.sub.s corresponding to the respective focal
lengths f as the look-up table 146, a predetermined drive voltage
E.sub.0 is applied to the optical element 101 by the power supply
means 131 with reference to the table 146. The capacitance
detection means 161 detects the detected voltage E.sub.SR at that
time (S3142) and judges whether or not the E.sub.SR value is equal
to the read out Es from the look-up table 146 in the CPU 130
(S3143). Here the both parties coincide, the state returns to the
step S3102, but if they do not coincide, the state will shift to
S3151 and onward. Incidentally, in some cases of the characteristic
of the optical apparatus, the step S3143 may pick up not only
complete agreement between the actual detected voltage E.sub.SR and
the value in the look-up table 146 but also may be caused to permit
a certain degree of range.
[0403] In the step S3151 it is judged whether or not the value of
the detected voltage E.sub.SR is within a predetermined range, and
if within the range, the state shifts to the step S3152. If it is
out of the range, the optical element 101 is judged to suffer from
failure, and the state shifts to the step S3161 to display the
failure on the display 151 (S3161) and cancel the photo-taking
operation (S3162). Incidentally, in some cases of the
characteristic of the optical apparatus, the range of the step
S3151 may either be a little wider or be a little narrower.
[0404] On the other hand, in the step S3152 an alarm is displayed
onto the display 151 so that the corrected voltage V is calculated
by the equation (1) (S3153), and based on that calculation outcome
the corrected voltage V is applied to the optical element 101 by
the power supply means 131 (S3154). 1 V = [voltageVforprevioustime]
+ E S - E SR 2 ( 1 )
[0405] In addition the state returns to the step S3142. That is,
the step S3142 to S3154 are repeated until the detected voltage
value E.sub.SR agrees with the voltage E.sub.s read out from the
look-up table 146.
[0406] In addition, when the both parties agree, the state returns
to the step S3102. That is, in the case where the zoom switch 153
is kept in operation, the step S3102 to the step S3123 are
repeatedly executed and at the time point when the on-operation of
the zoom switch S153 is completed, the state shifts to the step
S3104.
[0407] In the step S3104 distinction on whether or not on-operation
on the pre-photo-taking switch (indicated as SW1 in the flow chart
in FIG. 53) among the operation switches 154 has been executed by
the photographer is implemented. In the case where the on-operation
is not executed, the state returns to the step S3102 so that
acceptance for setup of photographic conditions and distinguishing
on operation of zoom switch 153 is repeated. Once the
pre-photo-taking switch is determined to have been operated on in
the step S3104, the process continues on to the step S3111.
[0408] Incidentally, the onward steps are approximately the same as
the above described respective embodiments, descriptions thereon
will be omitted.
[0409] According to the above described twelfth embodiment, by
utilizing the drive electrode of the optical element in the optical
element having a capacitor structure, its capacitance can be
detected. In addition, since changes in capacitance corresponds not
with changes in distance but with changes in area, capacitance can
be detected accurately.
[0410] In addition, in the optical apparatus in which the optical
element having capacitor structure was incorporated, by detection
of capacitance of the optical element, control the applying voltage
to the optical element for obtaining desired focal distance can be
executed. In addition, there are effects that failure of the
optical apparatus can be detected.
[0411] Incidentally, also in this embodiment, as an example of the
optical element, a digital still camera was taken, but it goes
without saying that also a video camera or a silver halide film
camera, etc. other than that can be taken likewise without spoiling
the effects.
[0412] [Thirteenth Embodiment]
[0413] FIG. 55 to FIG. 57 are drawings related to the thirteenth
embodiment of the present invention, and the optical element 801 in
FIG. 55 is the one with configuration shown in FIG. 16, and
therefore, descriptions thereon will be omitted.
[0414] In this embodiment, as in the twelfth embodiment, reference
numeral 161 denotes the capacitance detection means to detect
capacitance of the optical element 801, and the optical apparatus
150 will be exemplified, for description, by so-called digital
still camera which converts a still image into electric signals
with photo-taking means and records them as digital data.
Incidentally, as for those similar to the ones in the twelfth
embodiment, detailed description thereon will be omitted.
[0415] In FIG. 55, reference numeral 430 denotes a photo-taking
optical system comprising a plurality of lens groups and are
configured by first lens group 431, second lens group 432, and the
third lens group 433. Forward and backward movement in the optical
axis of the first lens group 431 implements focus adjustment.
Forward and backward movement in the optical axis of the second
lens group 432 implements zooming. The third lens group 433 is a
relay lens group without movement. In addition, an optical element
801 is disposed between the second lens group 432 and the third
lens group 433. In addition, the photo-taking means 430 is disposed
in the focusing position (planned image forming surface) of the
photo-taking optical system 144.
[0416] The optical element 801 in this embodiment is the one which
is used as a variable ND filter.
[0417] FIG. 56 and FIG. 57 are a control flow chart on the CPU 130
which the optical apparatus 150 having been shown in FIG. 55 has.
The control flow of the optical apparatus 150 will be described
with reference to FIG. 55 as well as FIG. 56 as follows.
Incidentally, as for the control flow similar to that in the above
described embodiment, detailed description thereof will be
omitted.
[0418] In the step S3201, distinction on whether or not
on-operation of the main switch 152 is executed by the photographer
is implemented and when the on-operation is not yet executed, the
state remains in the step S3201.
[0419] In the step S3201, when on-switch operation of the main
switch 152 is distinguished, the CPU 130 gets out of the sleep
state so as to execute the step S3202 and onward.
[0420] In the step S3202 setup of photographic conditions by a
photographer is accepted.
[0421] In the step S3203 it is distinguished whether or not
on-operation on the pre-photo-taking switch (indicated as SW1 in
the flow chart) has been executed by the photographer. In the case
where the on-operation is not executed, the state returns to S3202
so that distinguishing on acceptance for setup of photographic
conditions is repeated.
[0422] Once the pre-photo-taking switch is determined to have been
operated on in the step S3203, the process continues on to the step
S3211.
[0423] Since the step S3211 as well as the step S3212 is similar to
those in the twelfth embodiment, description thereon will be
omitted.
[0424] In the step S3213 it is distinguished whether or not the
received light amount judged in the above described step S3212 is
appropriate.
[0425] In addition, when in the present step its appropriateness is
recognized, the process continues to the step S3214.
[0426] On the other hand, when in the step S3213 it is
distinguished that the received light amount judged in the above
described step S3212 is not appropriate, the state leaps to the
step S3221.
[0427] In the step S3221 the appropriate transmittance is
calculated, after the calculation is completed, the process
continues to the subroutine of "applying voltage control" of the
next step S3222.
[0428] In the step S3241 the drive voltage E.sub.0 is calculated in
order to acquire the appropriate transmittance calculated in the
above described step S3221. In particular, since the ROM inside the
CPU 130 stores the relationship between the drive voltage E.sub.0
and the detected voltage E.sub.s corresponding to the respective
the transmittance as the look-up table 146, a predetermined drive
voltage Eo is applied to the optical element 101 by the power
supply means 131 with reference to the table.
[0429] The capacitance detection means 161 detects the detected
voltage E.sub.SR at that time (S3242) and judges whether or not the
E.sub.SR value is equal to the read out E.sub.s from the look-up
table 146 in the CPU (S3243).
[0430] Here the both parties coincide, the state returns to the
step S3202, but if they do not coincide, the state will shift to
S3251 and onward.
[0431] Incidentally, in some cases of the characteristic of the
optical apparatus, in the step S3243 the coincidence may mean not
only complete agreement between the actual detected voltage
E.sub.SR and the value in the look-up table 146 but also may be
caused to permit a certain degree of range. In the step S3251 it is
judged whether or not the value of the detected voltage E.sub.SR is
within a predetermined range, and if within the range, the state
shifts to the step S3252. If it is out of the range, the optical
element 101 is judged to suffer from failure, and the state shifts
to the step S3261 to display the failure on the display 151 (S3261)
and cancel the photo-taking operation (S3262). Incidentally, in
some cases of the characteristic of the optical apparatus, the
range of the step S3151 may either be a little wider or be a little
narrower.
[0432] On the other hand, in the step S3252 an alarm is displayed
onto the display 151 so that the corrected voltage V is calculated
by the equation (2) (S3253), and based on that calculation outcome
the corrected voltage V is applied to the optical element 801 by
the power supply means 131 (S3254). 2 V = [voltageVforprevioustime]
+ E S - E SR 2 ( 2 )
[0433] In addition the state returns to the step S3242. That is,
the step S3242 to S3254 are repeated until the detected voltage
value E.sub.SR agrees with the voltage E.sub.s read out from the
look-up table 146.
[0434] Since the step S3214 to the step S3237 are similar to those
in the twelfth embodiment, descriptions thereon will be
omitted.
[0435] As described so far, in the optical apparatus in which the
optical element having capacitor structure was incorporated,
detection of capacitance of the optical element can control the
applying voltage to the optical element for obtaining desired
transmittance. In addition, there are effects that failure of the
optical apparatus can be detected.
[0436] Incidentally, also in this embodiment, as an example of the
optical element, a digital still camera was taken, but it goes
without saying that also a video camera or a silver halide film
camera, etc. other than that can be taken likewise without spoiling
the effects.
* * * * *